This service manual provides detailed, step-by-step instructions for the maintenance, repair, and overhaul of the John Deere 4255 tractor. It is designed to assist experienced mechanics and qualified technicians in performing a wide range of procedures, from basic servicing to complex component rebuilds. Throughout this manual, you will find detailed diagrams, exploded views, and precise specifications, all meticulously compiled to ensure accurate and efficient troubleshooting and repair. Remember, using this manual effectively requires a solid understanding of mechanical principles and safe working practices, and should be used in conjunction with experience in the field.
The information contained herein is current as of the date of publication. However, due to ongoing product improvements and design changes, John Deere reserves the right to make revisions without prior notice. Therefore, it is essential to verify any critical specifications or procedures with the latest available service information from John Deere before commencing any repair work. Always cross-reference part numbers and torque values to ensure you are using the correct components and applying the appropriate fastening techniques. Taking this extra step will prevent damage to the equipment and ensure the longevity of the tractor.
Safety is paramount when working on any piece of machinery, especially a powerful tractor like the John Deere 4255. Before beginning any maintenance or repair procedure, thoroughly review and understand all safety instructions and warnings outlined in this manual and in the tractor's operator's manual. Always disconnect the battery cables before working on the electrical system or performing any task that could potentially create a short circuit. Failure to do so could result in electrical shock or damage to the tractor's components.
Always use appropriate personal protective equipment (PPE), including safety glasses, gloves, and sturdy footwear. Be aware of potential hazards such as hot surfaces, sharp edges, and rotating parts. When working under the tractor, ensure it is securely supported by jack stands or other suitable lifting devices. Never rely solely on a hydraulic jack for support. Exercise caution when handling fuels, lubricants, and other chemicals, and dispose of them properly according to local regulations. Keep your work area clean and organized to prevent accidents and ensure efficient workflow. Remember, your safety and the safety of those around you are always the top priority.
This manual covers the major systems of the John Deere 4255 tractor, including the engine, transmission, axles, hydraulics, electrical system, and operator station. Each section provides detailed information on component identification, operation, troubleshooting, and repair. Use the table of contents to quickly locate the section relevant to the specific issue you are addressing. Familiarize yourself with the various symbols and abbreviations used throughout the manual to ensure accurate interpretation of the instructions.
Whenever possible, use genuine John Deere parts and components to ensure optimal performance and reliability of your tractor. Genuine parts are designed and manufactured to meet John Deere's stringent quality standards and are backed by a comprehensive warranty. Before ordering parts, always verify the tractor's serial number to ensure you are selecting the correct components for your specific model. Proper maintenance and timely repairs are crucial for extending the life of your John Deere 4255 and maximizing its productivity. By following the guidelines outlined in this manual, you can keep your tractor running smoothly for years to come.
Removing the engine from your John Deere 4255 is a significant undertaking and should only be performed with adequate workspace, tools, and mechanical experience. Before starting any removal procedures, ensure the tractor is safely parked on a level surface, the parking brake is engaged, and the wheels are securely blocked. Disconnect the negative battery cable to prevent accidental electrical shorts. Thoroughly clean the engine and surrounding areas to minimize the introduction of dirt and debris during disassembly. Document the location and routing of all hoses, wires, and linkages before disconnecting them, as this will significantly aid in the reinstallation process.
Begin by draining all fluids, including coolant, engine oil, and fuel, into appropriate containers for proper disposal. Disconnect and label all electrical connections, fuel lines, and coolant hoses attached to the engine. Carefully remove all belts, including the alternator belt, water pump belt, and any others connected to the engine's pulleys. Disconnect the exhaust system from the engine, ensuring to support the weight of the exhaust components to prevent damage. Finally, disconnect the throttle linkage, fuel shut-off lever, and any other mechanical connections to the engine.
With all connections removed, prepare for the actual engine lift. Attach an engine hoist to the designated lifting points on the engine. Double-check that the hoist is securely attached and that the engine is balanced. Slowly and carefully lift the engine out of the tractor, ensuring that it clears all surrounding components. Once the engine is clear, carefully lower it onto a suitable engine stand for servicing. Remember to label and store all removed parts in an organized manner to facilitate reassembly. Installation is the reverse of removal, but always consult the torque specifications in this manual when tightening any bolts or fasteners.
The cylinder head is a critical component of the engine, housing the valves, springs, and rocker arms. Servicing the cylinder head often involves removing it from the engine block. Always allow the engine to cool completely before attempting to remove the cylinder head, as the metal will be extremely hot and could cause burns. Before removal, thoroughly clean the cylinder head and surrounding area to prevent debris from entering the engine. Disconnect all necessary connections, including fuel lines, coolant hoses, and wiring harnesses. Carefully remove the intake and exhaust manifolds from the cylinder head.
Loosen the cylinder head bolts in the reverse order of the tightening sequence specified in the service manual. This is crucial to prevent warping or damage to the cylinder head. Once all bolts are loosened, carefully remove them and lift the cylinder head from the engine block. Inspect the cylinder head gasket for any signs of damage or leaks. Thoroughly clean the cylinder head and engine block surfaces, removing any traces of the old gasket material. Inspect the cylinder head for cracks, warping, or other damage. Use a straightedge and feeler gauge to check for warping. If the cylinder head is warped beyond acceptable limits, it may need to be resurfaced by a qualified machine shop.
Once the cylinder head is clean and inspected, you can proceed with valve service. Use a valve spring compressor to remove the valve springs, retainers, and valves. Inspect the valves for wear, damage, or carbon buildup. Clean the valve seats and valve faces using a valve grinding tool or a qualified machine shop. Replace any worn or damaged valve guides. Install new valve stem seals. Reassemble the valves, springs, and retainers, ensuring they are properly seated. Install the cylinder head back onto the engine block using a new cylinder head gasket. Tighten the cylinder head bolts in the specified sequence and to the correct torque.
The valve train of the John Deere 4255 engine is responsible for opening and closing the intake and exhaust valves at the correct times. This intricate system includes components such as the camshaft, pushrods, rocker arms, valves, and valve springs. Regular inspection and maintenance of the valve train are crucial to ensure optimal engine performance and longevity. Common issues include worn camshaft lobes, bent pushrods, damaged rocker arms, and weakened valve springs.
Start by inspecting the camshaft for wear. Remove the valve cover and visually inspect the camshaft lobes for any signs of rounding or pitting. Use a dial indicator to measure the camshaft lobe lift. Compare your measurements to the specifications in this manual. If the lobe lift is significantly reduced, the camshaft needs replacement. Next, check the pushrods for straightness. Roll the pushrods on a flat surface to identify any bending. Replace any bent pushrods.
Inspect the rocker arms for wear at the valve stem contact point and the pushrod socket. Replace any rocker arms that exhibit excessive wear or damage. Examine the valve springs for cracks or breaks. Use a valve spring tester to check the spring pressure. Compare your measurements to the specifications in this manual. Replace any valve springs that do not meet the specifications. Finally, check the valve lash, or valve clearance. Use a feeler gauge to measure the gap between the rocker arm and the valve stem. Adjust the valve lash to the specified value.
The lubrication system is the lifeblood of the John Deere 4255 engine. It ensures that all moving parts are adequately lubricated, reducing friction, wear, and heat. A properly functioning lubrication system is essential for engine longevity and performance. The key components of the system include the oil pump, oil filter, oil cooler (if equipped), oil pressure sensor, and oil galleries.
Regular oil changes are paramount for maintaining a healthy lubrication system. Follow the recommended oil change intervals specified in this manual. Use the correct type and viscosity of engine oil. Inspect the oil filter during each oil change. Replace the oil filter if it is clogged or damaged. Check the oil pressure regularly. Low oil pressure can indicate a problem with the oil pump, oil filter, or oil galleries. Investigate and address any oil pressure issues immediately.
The oil pump is responsible for circulating oil throughout the engine. If the oil pump fails, the engine will quickly suffer severe damage. Check the oil pump for wear or damage. Replace the oil pump if necessary. Inspect the oil galleries for blockage or leaks. Clean out any clogged oil galleries. Check the oil cooler (if equipped) for leaks or damage. Repair or replace the oil cooler as needed. Keep a watchful eye on the system.
The cooling system of your John Deere 4255 engine prevents overheating by dissipating excess heat. The key components of the system are the radiator, water pump, thermostat, coolant hoses, and coolant reservoir. A properly functioning cooling system is vital for engine longevity and optimal performance. A neglected system can quickly result in catastrophic engine failure. Therefore, ensuring it works is vital for your machine.
Regularly check the coolant level in the coolant reservoir. Maintain the coolant level within the recommended range. Inspect the coolant hoses for cracks, leaks, or swelling. Replace any damaged coolant hoses. Check the radiator for leaks, damage, or blockage. Clean the radiator fins to ensure proper airflow. Test the thermostat to ensure it is opening and closing at the correct temperature. Replace the thermostat if it is faulty.
The water pump circulates coolant throughout the engine. If the water pump fails, the engine will quickly overheat. Check the water pump for leaks or damage. Replace the water pump if necessary. Use the correct type and concentration of coolant. Mixing different types of coolant can cause corrosion and damage to the cooling system. Perform a cooling system flush periodically to remove contaminants and deposits. Address any cooling system issues promptly to prevent engine damage. Keep your machine running.
The fuel system of the John Deere 4255 engine delivers the correct amount of fuel to the engine for combustion. Key components include the fuel tank, fuel lines, fuel filter, fuel injection pump, and injectors. A properly functioning fuel system ensures optimal engine performance, fuel efficiency, and reduced emissions. Understanding its parts and problems will help you prevent downtime.
Regularly inspect the fuel tank for leaks, damage, or contamination. Clean the fuel tank if necessary. Check the fuel lines for cracks, leaks, or blockages. Replace any damaged fuel lines. Replace the fuel filter at the recommended intervals. A clogged fuel filter can restrict fuel flow and reduce engine performance. Drain water and sediment from the fuel filter regularly to prevent contamination of the fuel system. Using high-quality fuel protects your system.
The fuel injection pump delivers fuel to the injectors at the correct pressure and timing. If the fuel injection pump is faulty, the engine may experience reduced performance, hard starting, or excessive emissions. Inspect the fuel injectors for leaks, damage, or blockage. Clean or replace the fuel injectors as needed. Ensure all fuel system connections are tight and leak-free. Address any fuel system issues promptly to prevent engine damage and ensure optimal performance. Remember, a well-maintained fuel system is key to a healthy engine.
Understanding the wiring diagrams for your John Deere 4255 is crucial for troubleshooting any electrical issues. These diagrams provide a visual representation of the entire electrical circuit, including the location of components, the wire colors, and the connections between them. A detailed understanding will allow you to trace circuits, identify shorts, and verify proper connections, ensuring efficient and safe repairs. Always refer to the specific wiring diagram for your tractor's serial number range as there might be variations over the production years. Remember to always disconnect the battery before working on the electrical system to avoid short circuits and potential injury.
Before attempting any electrical repairs, familiarize yourself with the symbols and conventions used in the wiring diagrams. Understanding the meaning of each symbol, such as resistors, capacitors, and relays, will enable you to accurately interpret the diagrams. Look for keys or legends that explain the different symbols and wire color codes. Wire color codes are especially important; they allow you to quickly identify and trace wires within the harness. It is always wise to have the correct tools, such as a multimeter to test continuity and voltage to allow for an efficient diagnosis. With proper understanding and the right tools, using the wiring diagram will allow for any electrical issue to be diagnosed and repaired.
The starting system is responsible for cranking the engine until it reaches a speed sufficient for self-sustaining combustion. This system primarily consists of the battery, starter motor, solenoid, and associated wiring. A fully charged battery is essential for providing the necessary power to turn the starter motor. The solenoid acts as a relay, using a small amount of current from the ignition switch to control the large current flow to the starter motor. It is critical to perform regular checks on the battery terminals, and all connections for corrosion or loose connections, as these conditions can severely impact the starting performance. If any issues occur during startup it is extremely important to get it fixed to keep the tractor running efficiently.
If the engine fails to crank, or cranks slowly, systematically troubleshoot the starting system. Start by verifying the battery voltage. If the voltage is low, charge or replace the battery. Next, check the solenoid for proper operation. You can test the solenoid by applying voltage to the small terminal and listening for a click, this signifies that the solenoid is operational. If the solenoid clicks but the starter does not engage, there may be a problem with the starter motor itself, like worn brushes or a faulty armature. Remember, safety is paramount, always disconnect the battery ground cable before working on the starting system, and consult the wiring diagram to verify the correct connections. Keep your starting system in working order to keep your tractor up and running.
The charging system is responsible for maintaining the battery's charge and providing power to the electrical components while the engine is running. The core components of the charging system include the alternator or generator, voltage regulator, and wiring. The alternator converts mechanical energy from the engine into electrical energy, which is used to charge the battery and power the electrical loads. The voltage regulator controls the output of the alternator, ensuring that the battery receives the correct voltage to prevent overcharging or undercharging. Regular inspection of the alternator belt tension is essential to ensure proper charging performance, and ensure the battery posts are clean.
To troubleshoot charging system issues, begin by checking the alternator belt for wear and proper tension. A loose or worn belt can cause insufficient charging. Next, use a voltmeter to measure the battery voltage with the engine running. The voltage should typically be between 13.5 and 14.5 volts. If the voltage is outside this range, the voltage regulator may be faulty and require replacement. Also, inspect the wiring connections for corrosion or loose connections, which can impede the flow of current. Remember to consult the wiring diagram for your tractor model to identify the correct wiring connections and test points. Always be careful when diagnosing any electrical issues.
The lighting system provides illumination for safe operation during low-light conditions. The system includes headlights, taillights, work lights, and turn signals, along with associated wiring, switches, and relays. Regular inspection of the lighting system is essential to ensure all lights are functioning properly. Burnt-out bulbs should be replaced immediately to maintain visibility and prevent accidents. Pay close attention to the condition of the headlight lenses, which can become cloudy or damaged over time, reducing light output. Replacing cloudy or damaged lenses will significantly improve visibility in low-light conditions. A lighting system is integral to keeping the operator safe.
When troubleshooting lighting system problems, start by checking the bulbs for continuity using a multimeter. If the bulb is good, inspect the wiring connections for corrosion or loose connections. Also, verify the condition of the switches and relays associated with the lighting circuits. A faulty switch or relay can prevent the lights from turning on. Use the wiring diagram to trace the circuits and identify the location of the switches and relays. Remember to always disconnect the battery ground cable before working on the electrical system to prevent short circuits and potential injury. Keep your lighting systems working so you are able to work safer in dark conditions.
The instrument panel provides critical information to the operator, including engine temperature, oil pressure, fuel level, and other vital parameters. The instrument panel also houses the warning lights and gauges that alert the operator to potential problems. Proper functioning of the instrument panel is crucial for monitoring the tractor's performance and preventing costly damage. Regular inspection of the instrument panel is essential to ensure all gauges and lights are working correctly. Pay close attention to the warning lights, which can indicate potential problems with the engine, transmission, or other systems.
If a gauge or warning light is not functioning properly, start by checking the wiring connections to the instrument panel. Loose or corroded connections can disrupt the flow of current and cause the gauges or lights to malfunction. Use the wiring diagram to identify the correct wiring connections for each gauge and warning light. If the wiring connections are good, the gauge or sensor itself may be faulty and require replacement. Remember to always consult the wiring diagram for your tractor model to verify the correct wiring connections and test points. The instrument panel is important, so be sure to diagnose any potential issues.
The John Deere 4255 transmission is a complex piece of machinery, responsible for delivering power from the engine to the wheels. Before undertaking any disassembly, it is crucial to consult the complete service manual and familiarize yourself with the exploded diagrams and parts lists. This will ensure you understand the location and function of each component, preventing costly errors and facilitating a smoother reassembly process. Always use the correct tools and torque specifications as outlined in the manual to avoid damaging delicate parts like gears, bearings, and seals. Furthermore, keep all components organized and labeled during disassembly to aid in proper reinstallation later.
Disassembly should begin with draining all the transmission oil. This minimizes mess and potential spills. Carefully remove any external components such as hydraulic lines, sensors, and covers. Pay close attention to the order of removal and make notes or take photos to assist in reassembly. As you disassemble the gearbox, inspect each part for wear, damage, or corrosion. Replace any parts that show signs of wear or damage, as this can prevent future failures and ensure the long-term reliability of the transmission. Take the opportunity to clean each component thoroughly before reassembly.
Reassembly is the reverse of disassembly, but with an added emphasis on precision and lubrication. Before installing any parts, apply a liberal coating of clean transmission oil to all bearing surfaces, gears, and seals. This will reduce friction and prevent premature wear during initial operation. Ensure that all seals are properly seated and oriented to prevent leaks. Use new gaskets and O-rings wherever possible to ensure a tight seal. Carefully tighten all bolts and fasteners to the specified torque values. Over-tightening can damage the components, while under-tightening can lead to leaks and loosening.
The hydraulic system within the 4255 transmission is vital for various functions, including shifting gears, operating the power take-off (PTO), and controlling the differential lock. This system relies on a hydraulic pump to generate pressure, a network of valves to control flow, and hydraulic cylinders to actuate the desired mechanisms. Proper maintenance of the hydraulic system is crucial for maintaining the overall performance and reliability of the tractor. Regularly check the hydraulic fluid level and condition, and replace the fluid and filter according to the manufacturer's recommendations.
Troubleshooting hydraulic issues requires a systematic approach. Start by checking the oil level and ensuring that the pump is operating correctly. Use a pressure gauge to verify that the hydraulic system is producing the correct pressure. If the pressure is low, check for leaks in the lines and fittings. Inspect the valves for proper operation. A malfunctioning valve can cause a variety of problems, including slow shifting, PTO failure, and differential lock issues. Clean or replace any valves that are not functioning correctly. A clogged hydraulic filter can also restrict flow and reduce pressure, so be sure to inspect and replace it as needed.
When working on the hydraulic system, cleanliness is paramount. Dirt and debris can quickly damage the sensitive components and cause malfunctions. Always use clean tools and work in a clean environment. Before disconnecting any hydraulic lines, relieve the pressure in the system to prevent spills and potential injury. When reconnecting hydraulic lines, make sure they are properly tightened to prevent leaks. After completing any repairs or maintenance, bleed the hydraulic system to remove any air that may have entered the lines. Air in the hydraulic system can cause erratic operation and reduced performance.
The differential is a crucial component that allows the rear wheels to rotate at different speeds when the tractor is turning. This prevents tire slippage and damage to the drivetrain. The differential consists of a series of gears that distribute power to the wheels while allowing for variations in speed. Regular maintenance of the differential is essential for maintaining its smooth and efficient operation. Check the differential oil level regularly and replace the oil according to the manufacturer's recommendations.
Diagnosing differential problems can sometimes be challenging. Common issues include excessive noise, vibration, and wheel slippage. These problems can be caused by worn gears, damaged bearings, or insufficient lubrication. To inspect the differential, you will need to drain the oil and remove the differential housing cover. Carefully examine the gears for signs of wear or damage, such as chipped teeth or excessive play. Check the bearings for smoothness and any signs of wear or roughness. If any parts are worn or damaged, they should be replaced.
When reassembling the differential, be sure to use the correct shims and spacers to achieve the proper gear backlash. This is the amount of play between the gears and is critical for preventing excessive noise and wear. Consult the service manual for the correct backlash specifications. Apply a liberal coating of clean differential oil to all bearing surfaces and gears before reassembly. Tighten all bolts and fasteners to the specified torque values. After reassembling the differential, check for leaks and ensure that the wheels rotate smoothly and quietly.
The final drives are the last stage of the transmission system, responsible for transmitting power from the differential to the wheels. They consist of a set of gears that reduce the speed and increase the torque, providing the necessary power to drive the tractor. Final drives are subjected to high loads and require regular maintenance to ensure their reliable operation. Regularly check the final drive oil level and replace the oil according to the manufacturer's recommendations.
Common final drive problems include oil leaks, excessive noise, and wheel bearing failures. Oil leaks can be caused by damaged seals or worn bearings. Excessive noise can be a sign of worn gears or damaged bearings. Wheel bearing failures can result in excessive play in the wheels and can eventually lead to complete failure. To inspect the final drives, you will need to remove the wheels and the final drive housing covers. Carefully examine the gears for signs of wear or damage. Check the bearings for smoothness and any signs of wear or roughness. If any parts are worn or damaged, they should be replaced.
When reassembling the final drives, be sure to use the correct seals and bearings. Apply a liberal coating of clean final drive oil to all bearing surfaces and gears before reassembly. Tighten all bolts and fasteners to the specified torque values. After reassembling the final drives, check for leaks and ensure that the wheels rotate smoothly and quietly. Be sure to perform a thorough inspection to ensure everything is put back together correctly before operating the tractor under normal conditions. Addressing issues early can prevent more serious problems down the line.
The John Deere 4255 tractor relies heavily on its hydraulic system for a multitude of functions, including steering, braking, implement lifting, and powering auxiliary equipment. This robust system is designed for high efficiency and reliability, but understanding its key components and their proper operation is critical for maintenance and troubleshooting. Proper maintenance is key to ensuring the longevity of the hydraulic system and its ability to perform all required tasks to keep your tractor running smoothly. Neglecting even minor maintenance tasks can lead to reduced performance, costly repairs, and ultimately, downtime that impacts your productivity.
The hydraulic pump is the heart of the system, responsible for generating the pressure needed to operate hydraulic functions. The 4255 typically utilizes a gear-type pump, known for its durability and relatively simple design. The pump draws hydraulic fluid from the reservoir and forces it through the system under high pressure. It is crucial to regularly inspect the pump for leaks, unusual noises, or signs of wear. Pay close attention to the pump's drive shaft coupling and ensure it is properly aligned and secured, as misalignment can cause premature pump failure.
Maintaining the correct hydraulic fluid level is crucial for optimal pump performance and longevity. Low fluid levels can lead to cavitation within the pump, causing significant damage to internal components. In addition, ensure that you are using the appropriate hydraulic fluid specified by John Deere for your 4255 model. Using the wrong type of fluid can lead to corrosion, seal degradation, and reduced hydraulic system efficiency. Regularly check the hydraulic fluid filter and replace it according to the recommended service schedule, as a clogged filter restricts fluid flow and puts unnecessary strain on the pump.
Control valves manage the flow of hydraulic fluid to various components, allowing for precise control over the tractor's functions. These valves are typically spool-type valves, which slide within a valve body to direct fluid flow to different circuits. Proper adjustment and maintenance of these valves are essential for smooth and responsive operation. Over time, control valves can experience wear and tear, leading to internal leakage and reduced performance. Signs of valve issues include slow or erratic movement of hydraulic cylinders, difficulty maintaining implement position, and excessive heat buildup in the hydraulic system.
Regularly inspect the control valve linkages and ensure they are properly lubricated and adjusted. Tight or binding linkages can cause the valve spools to stick, resulting in jerky or unresponsive operation. Check the valve body for external leaks and address them promptly to prevent fluid loss and potential contamination. When troubleshooting hydraulic issues, it is often helpful to systematically isolate each control valve to determine if it is the source of the problem. Using a pressure gauge, you can measure the pressure at different points in the system to pinpoint the location of any restrictions or leaks.
Hydraulic cylinders convert hydraulic pressure into linear motion, powering implements such as loaders, mowers, and tillage equipment. These cylinders consist of a barrel, piston, rod, and seals, all working in concert to provide the necessary force for lifting and positioning. Regularly inspect the cylinders for signs of damage, such as dents, scratches, or corrosion on the piston rod. These imperfections can damage the seals and lead to leaks.
Pay close attention to the cylinder seals, as they are the most common source of leaks. Look for fluid weeping around the seals or evidence of oil collecting on the cylinder body. Replace worn or damaged seals promptly to prevent further damage to the cylinder components. When replacing seals, ensure that you use the correct type and size specified for your John Deere 4255 tractor. In addition, be sure to properly bleed the hydraulic system after any cylinder repairs to remove air from the lines and ensure smooth operation.
Diagnosing hydraulic system problems requires a systematic approach. Begin by thoroughly inspecting the system for obvious signs of leaks, damage, or wear. Check the hydraulic fluid level and condition, ensuring it is within the recommended range and free from contamination. Listen for unusual noises, such as whining, squealing, or knocking, which can indicate pump problems or air in the system.
Using a pressure gauge, measure the hydraulic pressure at various points in the system to identify restrictions or leaks. Compare the readings to the specifications in the service manual to determine if the system is operating within the correct parameters. If you suspect a problem with a specific component, such as the pump or a control valve, isolate it from the rest of the system to determine if it is the source of the issue. Always consult the John Deere 4255 service manual for specific troubleshooting procedures and recommended repair techniques. Remember to prioritize safety when working on the hydraulic system. Relieve pressure before disconnecting any lines or components to prevent accidental injection injuries.
The power steering pump is the heart of the hydraulic steering system, responsible for providing the necessary pressure to assist in turning the wheels. On the John Deere 4255, it is a robust, engine-driven component designed for demanding agricultural applications. Regular inspection and maintenance of the pump are crucial to ensure optimal steering performance and prevent costly repairs. This includes checking the hydraulic fluid level, inspecting for leaks, and monitoring the pump's overall condition for signs of wear or damage. Remember to always consult the tractor's operating manual for recommended maintenance intervals and fluid specifications.
Understanding the internal workings of the power steering pump can aid in troubleshooting potential issues. The pump typically consists of a rotating impeller or vane system that draws hydraulic fluid from the reservoir and pressurizes it. This pressurized fluid is then delivered to the steering valve, where it is directed to the appropriate side of the steering cylinder based on the operator's input. Any malfunction within the pump, such as worn vanes or internal leaks, can result in reduced steering assist or even complete loss of power steering. When diagnosing power steering problems, always start by verifying that the pump is receiving adequate hydraulic fluid and that the drive belt is properly tensioned. These simple checks can often reveal the root cause of the issue.
The steering cylinder, also known as the power steering ram, is the component that directly translates hydraulic pressure into mechanical force to steer the tractor. It is a double-acting cylinder, meaning it can apply force in both directions to assist in turning the wheels. The cylinder is connected to the tractor's steering linkage and is responsible for moving the wheels in response to the operator's input at the steering wheel. Proper function of the steering cylinder is essential for maintaining precise and responsive steering control.
Inspection of the steering cylinder should be part of routine maintenance. Check for signs of external leaks, damage to the cylinder rod, or wear on the mounting points. A leaking cylinder will result in a loss of hydraulic pressure, reducing steering assist. Damage to the cylinder rod can compromise its structural integrity and lead to premature failure. Additionally, inspect the hydraulic hoses and fittings connected to the cylinder for any signs of leaks or damage. These components are subjected to high pressure and can deteriorate over time, leading to reduced performance and potential safety hazards.
The steering valve acts as the control center for the hydraulic steering system. It precisely directs pressurized hydraulic fluid from the power steering pump to either side of the steering cylinder, based on the operator's steering wheel input. This allows the operator to effortlessly steer the heavy tractor with minimal physical effort. The steering valve is a complex component containing intricate internal passages and precisely machined parts. Maintaining its proper function is paramount for safe and effective steering control.
Troubleshooting issues with the steering valve often requires specialized knowledge and diagnostic tools. Common problems include internal leaks, sticking spools, and wear in the valve body. These issues can manifest as stiff steering, erratic steering response, or a complete loss of power steering assist. When diagnosing steering valve problems, it is essential to isolate the valve from the rest of the hydraulic system to determine if the issue lies within the valve itself or in another component, such as the power steering pump or steering cylinder. Because of the complexity, disassembly and repair of the steering valve are often best left to qualified technicians with the appropriate tools and expertise.
The John Deere 4255 brake system is a critical component for safe and efficient operation of the tractor. It's a hydraulically actuated, wet disc brake system, meaning that the brakes are immersed in oil to provide cooling and lubrication. This design is essential for dissipating the heat generated during heavy braking, especially during demanding field operations or when towing heavy loads. Understanding the overall system layout will greatly help in troubleshooting and maintaining the braking performance. The system consists of a master cylinder, brake lines, brake calipers with multiple discs, and the hydraulic reservoir. Properly functioning brakes are vital for preventing accidents and ensuring the operator has complete control over the tractor in all conditions.
The master cylinder, activated by the brake pedals, is what generates the hydraulic pressure needed to engage the brakes. When the brake pedals are depressed, the master cylinder pushes hydraulic fluid through the brake lines towards the brake calipers. Each brake caliper houses multiple friction discs that are compressed together when hydraulic pressure is applied. This compression creates friction, which in turn slows down or stops the rotation of the rear wheels. The wet disc design allows for smoother and more controlled braking compared to dry disc systems, as the oil cushions the engagement and prevents jerky movements. Moreover, the oil also acts as a coolant, preventing brake fade caused by excessive heat buildup.
Proper brake adjustment is paramount to ensure even and responsive braking performance. Uneven brake adjustment can cause the tractor to pull to one side during braking, which is a dangerous situation, especially at higher speeds. It is recommended to perform brake adjustment regularly, especially after periods of intense use or whenever you notice a change in braking performance. A typical symptom of misadjusted brakes includes a noticeable difference in the amount of pedal travel required to engage each brake or a general feeling of sluggishness when braking. It's important to consult the specific service manual for your John Deere 4255 tractor for the exact adjustment procedures, as there may be slight variations depending on the model year.
The adjustment process typically involves locating the adjustment mechanism on the brake calipers. This usually consists of a threaded rod or screw that can be turned to increase or decrease the clearance between the friction discs and the brake pads. The objective is to ensure that the brakes engage evenly and with minimal pedal travel. It is crucial to avoid over-tightening the brakes, as this can cause them to drag and overheat. After making adjustments, always test the brakes by driving the tractor at a slow speed and applying the brakes gently to verify that the tractor stops straight and without any unusual noises or vibrations. If the problem persists after adjustment, it may be necessary to inspect the brake components for wear or damage.
Brake repair on the John Deere 4255 can range from simple tasks like replacing worn brake pads to more complex procedures such as overhauling the master cylinder or brake calipers. Diagnosing brake problems requires careful observation and testing. Common issues include leaking hydraulic fluid, spongy brake pedal feel, reduced braking power, and unusual noises coming from the brakes. Before attempting any repairs, always disconnect the negative battery cable to prevent electrical shorts and ensure the tractor is properly supported to prevent accidental movement. Ensure you have the correct tools and replacement parts before starting the repair and always refer to the service manual for detailed instructions.
If the brake pads are worn, they must be replaced to maintain proper braking performance. To do this, the brake caliper has to be disassembled after which the old brake pads can be removed and replaced with new ones. After the reassembly of the brake caliper, bleed the brake system to remove any trapped air. If the master cylinder is leaking or not building pressure, it may need to be rebuilt or replaced. Rebuilding a master cylinder involves disassembling it, inspecting the internal components for wear or damage, and replacing any worn seals or pistons. Brake calipers can also leak or have sticking pistons, which will require a similar overhaul process. Always use genuine John Deere parts or high-quality aftermarket replacements to ensure compatibility and longevity. Remember that proper brake repair requires precision and attention to detail. If you're not comfortable performing these repairs yourself, it's best to consult a qualified mechanic.
The front axle on the John Deere 4255 is a robust component designed to withstand the rigors of heavy-duty agricultural work. Regular inspection and maintenance are crucial to ensure its longevity and optimal performance. This includes checking for any signs of wear, damage, or leakage around the axle housing, pivot points, and steering components. Lubrication is also vital; ensure all grease fittings are properly serviced with the correct type of grease, as specified in the lubrication chart. Ignoring these maintenance tasks can lead to premature failure of the axle, resulting in costly repairs and downtime.
The front axle assembly incorporates several critical elements, including the axle beam, steering knuckles, wheel hubs, and bearings. Each of these components plays a crucial role in the overall function of the axle. Periodically inspect the steering knuckles for play or looseness, as this can affect steering accuracy and stability. The wheel bearings should also be checked for proper lubrication and any signs of excessive wear or damage. Promptly addressing any issues with these components will prevent further damage and ensure safe operation of the tractor.
The rear axle on the John Deere 4255 is responsible for transmitting power from the transmission to the rear wheels, enabling the tractor to perform various tasks. Due to the significant loads and stresses it endures, the rear axle requires careful attention and regular maintenance. It is essential to regularly check the axle housing for any signs of leaks, cracks, or other damage, and to promptly address any issues found. Ignoring these warning signs can lead to severe mechanical failures and costly repairs.
The differential within the rear axle is a complex assembly that allows the wheels to rotate at different speeds during turns, preventing tire slippage and improving maneuverability. Inspecting the differential for proper lubrication and any unusual noises or vibrations is essential for ensuring smooth operation. Pay close attention to the axle seals, as these are prone to leakage, which can lead to a loss of lubricant and potential damage to the differential components. Regular maintenance and timely repairs will help prolong the lifespan of the rear axle and prevent costly breakdowns.
Removing and installing wheels on the John Deere 4255 should be performed with care and precision, following the manufacturer's recommended procedures. Begin by ensuring the tractor is parked on a level surface and the parking brake is engaged. Loosen the lug nuts before jacking up the tractor to the appropriate height using a suitable jack placed at the designated lifting points. Completely remove the lug nuts and carefully remove the wheel from the hub.
When installing the wheel, ensure the mating surfaces of the wheel and hub are clean and free of any debris. Align the wheel with the hub studs and carefully slide it into place. Hand-tighten the lug nuts in a star pattern, gradually increasing the torque until they are snug. Lower the tractor to the ground and use a torque wrench to tighten the lug nuts to the specified torque value. Recheck the lug nut torque after operating the tractor for a short period to ensure they remain properly tightened. Incorrectly installed wheels can pose a serious safety hazard.
Selecting the correct tires for the John Deere 4255 is crucial for optimal performance, traction, and safety. Consult the tractor's operator manual or a qualified tire specialist to determine the appropriate tire size, load rating, and tread pattern for your specific application. Using the wrong tires can negatively impact the tractor's handling, fuel efficiency, and overall performance. Regularly inspect the tires for signs of wear, damage, or improper inflation.
Maintaining proper tire pressure is essential for maximizing tire life and ensuring safe operation. Check the tire pressure regularly using an accurate tire gauge and adjust it according to the manufacturer's recommendations. Overinflating or underinflating the tires can lead to premature wear, reduced traction, and increased risk of tire failure. In addition to tire pressure, inspect the tires for cuts, bulges, or other damage that could compromise their structural integrity. Replace any damaged tires immediately to prevent accidents and ensure safe operation.
The air conditioning system in your John Deere 4255 is a complex, closed-loop system designed to provide comfortable cooling within the cab. Understanding the basic components and their functions is crucial for effective troubleshooting and maintenance. The system primarily consists of the compressor, condenser, evaporator, expansion valve, receiver-drier, and connecting hoses and lines. Each of these components plays a vital role in the refrigerant cycle, which is the process of transferring heat from inside the cab to the outside environment. Properly functioning components, adequate refrigerant charge, and leak-free connections are essential for optimal cooling performance. Regularly inspecting these elements can prevent costly repairs and ensure operator comfort, especially during demanding field work in hot conditions.
The refrigerant, typically R-134a in newer models, circulates throughout the system, absorbing and releasing heat as it changes state between liquid and gas. The compressor, driven by the engine, is the heart of the system, responsible for pressurizing the refrigerant and circulating it through the loop. The condenser, located in front of the radiator, dissipates heat from the high-pressure refrigerant, turning it into a high-pressure liquid. The expansion valve meters the flow of refrigerant into the evaporator, where it undergoes a rapid pressure drop and absorbs heat from the cab air, cooling it down. Finally, the receiver-drier filters the refrigerant and removes moisture, preventing damage to other components and ensuring efficient operation. Understanding this cycle will make subsequent troubleshooting and service procedures much more intuitive.
Servicing the air conditioning components requires careful attention to detail and adherence to safety procedures. Before beginning any work, ensure the system is properly discharged to remove the refrigerant. This should be done by a qualified technician using approved recovery equipment to prevent environmental damage and personal injury. When replacing any component, use only genuine John Deere parts or equivalent replacements that meet the manufacturer's specifications. Using incompatible parts can lead to system failures and potentially void warranties. Always refer to the specific service manual for your 4255 model for detailed instructions and torque specifications for each component.
The compressor should be regularly inspected for leaks, excessive noise, and proper clutch engagement. The condenser should be kept clean and free of debris to ensure efficient heat transfer. The evaporator, often located behind the dashboard, can accumulate dust and debris, hindering airflow and reducing cooling efficiency. Periodically cleaning the evaporator core is essential for maintaining optimal performance. The receiver-drier should be replaced periodically, typically every two to three years, or whenever the system is opened for service. This prevents moisture buildup and protects the compressor from damage. Checking the belts that drive the compressor for wear and proper tension is also a critical part of preventative maintenance.
Properly charging the air conditioning system with the correct amount of refrigerant is crucial for optimal cooling performance. Overcharging or undercharging the system can lead to reduced efficiency, component damage, and even system failure. Before charging the system, ensure that all leaks have been repaired and that the system has been properly evacuated to remove air and moisture. Use a vacuum pump to pull a deep vacuum on the system for at least 30 minutes, verifying that the vacuum holds steady before proceeding with charging. The amount of refrigerant required for your 4255 model is specified on a decal located near the compressor or in the service manual; adhere to this specification precisely.
When charging the system, use a refrigerant scale to accurately measure the amount of refrigerant being added. Monitor the system pressures during charging to ensure they are within the recommended ranges. The high-side and low-side pressures should be compared to the pressure-temperature charts in the service manual to ensure proper system operation. After charging, run the engine at idle and observe the cooling performance. Check the temperature of the air coming from the vents to ensure it is sufficiently cold. If the system is not performing as expected, further diagnostics may be required to identify the underlying issue. Remember to always use appropriate safety equipment, including gloves and eye protection, when working with refrigerant.
The hood and grille assembly on the John Deere 4255 serves multiple crucial functions. Primarily, it provides protection for the engine compartment, shielding vital components from the elements and potential damage from debris. The grille section is specifically designed to allow for optimal airflow to the radiator, ensuring proper engine cooling and preventing overheating, especially during periods of heavy use. Furthermore, the hood and grille contribute significantly to the overall aesthetic of the tractor, maintaining its iconic John Deere appearance. Regular inspection of this assembly is crucial, paying close attention to any cracks, dents, or loose mounting hardware that could compromise its structural integrity or impede airflow.
When performing maintenance or repairs that require access to the engine, proper hood removal is essential. Always consult the operator's manual for specific instructions, but generally, this involves releasing the hood latch mechanisms and carefully lifting the hood off its hinges or pivots. Before removing the hood, ensure that the tractor is parked on a level surface and the engine is turned off. It's also a good practice to have an assistant available to help with the lifting and handling of the hood, as it can be quite bulky and heavy. Securely store the hood in a safe location where it won't be damaged or become a safety hazard while you're working on the tractor.
Grille cleaning is a frequently overlooked but vital aspect of tractor maintenance. Over time, the grille can become clogged with dirt, leaves, and other debris, restricting airflow and potentially leading to engine overheating. Regularly inspect the grille and use a brush, compressed air, or a pressure washer to remove any accumulated debris. Exercise caution when using a pressure washer to avoid damaging the grille fins. Consider implementing a preventative maintenance schedule that includes regular grille cleaning to ensure optimal engine performance and longevity.
The operator's platform on the John Deere 4255 is designed with operator comfort and safety in mind. It provides a stable and ergonomically designed workspace for operating the tractor, housing essential controls such as the steering wheel, throttle, gear levers, and instrument panel. The platform also features non-slip surfaces to prevent accidents, particularly in wet or muddy conditions. It’s important to regularly inspect the platform for any signs of wear and tear, such as loose bolts, damaged floor mats, or corroded components.
Maintaining the cleanliness of the operator's platform is crucial for both safety and comfort. Accumulated dirt, mud, and debris can make it difficult to operate the controls and can also create slippery surfaces. Regularly clean the platform using a brush, vacuum cleaner, or a mild detergent solution. Pay particular attention to cleaning around the pedals and levers to ensure that they operate smoothly and without obstruction. A clean operator's platform not only improves the working environment but also allows for better visibility and control of the tractor.
The steps and handrails associated with the operator's platform are critical for safe entry and exit from the tractor. Ensure that these components are securely attached and free from any damage or corrosion. Regularly inspect the steps for signs of wear or cracking and replace them if necessary. Handrails should be firmly mounted and provide a secure grip. Making sure the entry points are properly maintained will reduce the risk of falls and injuries, especially in challenging terrains.
The seat on the John Deere 4255 is designed to provide maximum comfort and support for the operator during long hours of use. Many models feature adjustable suspension, lumbar support, and armrests to accommodate different body types and preferences. Proper seat adjustment is crucial for reducing fatigue and preventing back pain. Regularly inspect the seat for any signs of wear and tear, such as tears in the upholstery, loose springs, or damaged adjustment mechanisms. Addressing these issues promptly will ensure that the seat continues to provide the necessary support and comfort.
The seat restraints, including the seatbelt, are essential safety features that should always be used when operating the tractor. The seatbelt is designed to keep the operator securely in place in the event of an accident, reducing the risk of serious injury. Inspect the seatbelt regularly for any signs of fraying, tearing, or damage to the buckle. Replace the seatbelt immediately if any defects are detected. Encourage all operators to wear their seatbelts at all times, regardless of the length of the task.
Maintaining the seat suspension system is also important for a smooth and comfortable ride. The suspension system absorbs shocks and vibrations, reducing fatigue and improving operator control. Check the suspension components regularly for signs of wear or damage, such as leaking fluid or worn bushings. Lubricate the suspension components as recommended in the operator's manual. Proper maintenance of the seat suspension system will ensure a more comfortable and productive operating experience.
The Power Take-Off (PTO) system on your John Deere 4255 tractor is a critical component for powering various implements, from mowers and tillers to balers and sprayers. Proper maintenance and understanding of its operation are essential for safe and efficient operation. The PTO system transfers rotational power from the tractor's engine to the implement via a rotating shaft. This transfer relies on a series of gears, shafts, and clutches within the tractor's transmission and PTO unit. Before connecting any implement to the PTO, ensure both the tractor and the implement are switched off and the PTO lever is in the disengaged position. Always consult the implement's operator's manual for specific PTO speed and safety requirements, as exceeding the recommended PTO speed can damage the implement or the tractor's PTO system.
Regularly inspect the PTO shaft and its associated components for signs of wear, damage, or corrosion. Check the universal joints for excessive play or looseness. Grease the universal joints and slip clutch (if equipped) according to the lubrication schedule outlined in the tractor's operator's manual. Neglecting lubrication can lead to premature wear and failure of these critical components. Additionally, verify that the PTO safety shield is properly installed and in good condition. This shield is designed to protect the operator from accidental contact with the rotating PTO shaft. Never operate the PTO without the safety shield in place.
If you experience any issues with the PTO system, such as difficulty engaging or disengaging, unusual noises, or a loss of power, troubleshoot the problem systematically. Check the PTO lever linkage for proper adjustment. Inspect the clutch cable or hydraulic actuator for damage or leaks. Refer to the diagnostic procedures outlined in this service manual for detailed troubleshooting steps. Remember to always disconnect the PTO shaft and shut down the engine before performing any maintenance or repairs on the PTO system. When replacing PTO components, use only genuine John Deere parts to ensure proper fit and performance.
The three-point hitch is an indispensable attachment for connecting and operating a wide variety of rear-mounted implements. The three-point hitch uses two lower lift arms and a single top link to create a triangular connection point between the tractor and the implement. This design allows for precise control of implement height, angle, and depth. Understanding the adjustment procedures and safety precautions associated with the three-point hitch is crucial for safe and efficient operation. Always refer to both the tractor's and the implement's operator's manuals before connecting or operating any three-point hitch implement.
Before connecting an implement, ensure that the three-point hitch lift arms are properly adjusted for the size and weight of the implement. Adjust the length of the top link to achieve the correct implement angle. Utilize the sway bars or chains to prevent excessive side-to-side movement of the implement. When lifting heavy implements, gradually raise the lift arms to avoid sudden jolts or strains on the tractor's hydraulic system. Periodically inspect the lift arm pins, top link pin, and sway bar connections for wear or damage. Replace worn or damaged parts immediately to prevent implement detachment or instability. Also, regularly lubricate all pivot points on the three-point hitch to ensure smooth operation.
Troubleshooting issues with the three-point hitch often involves checking the hydraulic system. Verify that the hydraulic fluid level is correct and that there are no leaks in the hydraulic lines or cylinders. If the lift arms are slow to raise or lower, or if they do not maintain their position, inspect the hydraulic control valve for proper operation. Refer to the hydraulic system section of this service manual for detailed troubleshooting and repair procedures. Remember to relieve hydraulic pressure before disconnecting any hydraulic lines or components. Using the correct category three-point hitch implements are important to safe operation of your tractor.
The drawbar provides a crucial connection point for towing implements and trailers behind the John Deere 4255 tractor. It is designed to handle significant pulling forces, so proper attachment and maintenance are essential for safe and reliable towing. The drawbar is typically a heavy-duty steel bar that pivots vertically, allowing for turning movements while maintaining a secure connection to the towed implement. Different types of drawbars are available, including swinging drawbars and fixed drawbars, each designed for specific towing applications. Always select the appropriate drawbar type for the implement being towed.
Before towing any implement, carefully inspect the drawbar, hitch pin, and safety chain connections. Ensure that the hitch pin is properly secured with a cotter pin or locking device. Connect the safety chains to the implement's tongue and to the tractor's frame in a crisscross pattern. This provides a backup connection in case the primary hitch fails. Adjust the drawbar height to match the height of the implement's tongue for optimal towing stability. Distribute the load evenly on the towed implement to prevent excessive strain on the drawbar and hitch.
Regularly inspect the drawbar for signs of wear, cracks, or bending. Replace any damaged drawbar immediately. Lubricate the drawbar pivot points to ensure smooth movement. When towing heavy loads, use caution and reduce speed to maintain control of the tractor and implement. Avoid sudden starts and stops, which can place excessive stress on the drawbar and hitch. Adhering to these maintenance and operational practices will ensure the drawbar performs safely and reliably for years to come. Regularly check bolts to make sure they are tightened and not loose.
Diagnosing engine problems on the John Deere 4255 requires a systematic approach. Start by visually inspecting the engine for any obvious signs of damage, leaks, or loose connections. Check the engine oil level and coolant level to ensure they are within the acceptable ranges. A low oil level can indicate a leak or excessive oil consumption, while a low coolant level may point to a leak in the cooling system. Carefully examine the fuel lines and connections for any signs of cracks or leaks, as these can cause fuel starvation and poor engine performance. Also, listen for any unusual noises coming from the engine while it is running, as these could indicate internal damage or wear.
If the visual inspection doesn't reveal the problem, proceed to check the engine's starting system. Verify that the battery has sufficient charge and that the battery terminals are clean and free of corrosion. Test the starter motor to ensure it is operating correctly and engaging the flywheel properly. If the engine cranks slowly or not at all, the starter motor may be faulty or the battery may be weak. Additionally, inspect the wiring harness and connections to the starter motor for any signs of damage or corrosion, as these can cause starting problems. Use a multimeter to check for voltage drop in the starting circuit.
Once the engine is running (or attempting to run), check the fuel system. Ensure that the fuel filter is clean and not clogged, as a restricted fuel filter can cause a lack of power and poor engine performance. Bleed the fuel system to remove any air that may be present, especially after replacing the fuel filter or if the engine has been sitting for an extended period. Inspect the fuel injection pump for any signs of leakage or damage, and verify that the fuel injectors are functioning correctly. You can test the fuel injectors using specialized equipment to ensure they are delivering the correct amount of fuel at the proper pressure.
If the engine is still running poorly, check the air intake system. Make sure the air filter is clean and not clogged, as a restricted air filter can cause a lack of power and excessive smoke. Inspect the air intake hoses and connections for any leaks or damage, as these can allow unfiltered air to enter the engine. Also, check the turbocharger (if equipped) for proper operation, ensuring that it is not damaged or leaking oil. Perform a compression test to evaluate the condition of the engine's cylinders, as low compression can indicate worn piston rings, valves, or cylinder walls.
Troubleshooting transmission issues on the John Deere 4255 starts with observing the tractor's performance. Note any unusual noises, such as grinding or whining, coming from the transmission. Pay attention to any slipping or difficulty shifting between gears. Check the transmission oil level and condition. Low oil level or contaminated oil can lead to transmission damage and poor performance. Examine the transmission housing for any signs of leaks, which could indicate worn seals or gaskets. If any leaks are found, address them promptly to prevent further damage.
If the tractor is experiencing difficulty shifting, inspect the shift linkage for any signs of wear, damage, or misalignment. Adjust the shift linkage as necessary to ensure smooth and accurate gear selection. Check the clutch (if equipped) for proper operation. A worn or improperly adjusted clutch can cause slipping and difficulty shifting. Inspect the clutch linkage and adjust as needed to ensure proper engagement and disengagement. If the tractor has a power shift transmission, check the hydraulic pressure to the transmission. Low hydraulic pressure can cause shifting problems and reduced performance. Consult the service manual for the correct pressure specifications.
For hydrostatic transmissions, check the hydrostatic oil level and condition. Low oil level or contaminated oil can cause reduced power and poor performance. Inspect the hydrostatic pump and motor for any signs of leakage or damage. Perform a stall test to evaluate the hydrostatic transmission's performance. This involves holding the tractor against a fixed object and observing the engine RPM and transmission response. A failing hydrostatic transmission will often exhibit reduced power and sluggish response during a stall test. Check the hydrostatic control linkage for proper operation and adjustment.
Diagnosing hydraulic problems on the John Deere 4255 begins with a thorough visual inspection of the hydraulic system. Check all hydraulic hoses and connections for any signs of leaks or damage. Pay close attention to areas where hoses are exposed to friction or abrasion. Inspect the hydraulic cylinders for leaks around the seals or damage to the cylinder rods. Check the hydraulic oil level and condition. Low oil level or contaminated oil can lead to reduced hydraulic performance and damage to hydraulic components. Verify that the hydraulic filter is clean and not clogged.
If the hydraulic system is operating slowly or weakly, check the hydraulic pump pressure. Use a pressure gauge to measure the pressure at various points in the hydraulic system, following the procedures outlined in the service manual. Low hydraulic pressure can indicate a worn or damaged hydraulic pump. Inspect the hydraulic control valves for proper operation. Check for any sticking or binding of the valve spools. Clean or replace any valves that are not functioning correctly. Verify that the hydraulic relief valve is functioning properly to prevent over-pressurization of the system.
If certain hydraulic functions are not working, such as the loader or three-point hitch, trace the hydraulic lines and connections to those components. Look for any restrictions or blockages in the lines. Inspect the hydraulic cylinders associated with those functions for leaks or damage. Check the control valves that operate those functions for proper operation. Use a flow meter to measure the hydraulic flow rate to different components. This can help identify restrictions or problems with the hydraulic pump or control valves.
Troubleshooting electrical issues on the John Deere 4255 requires a multimeter and a good understanding of electrical circuits. Begin by checking the battery voltage. A fully charged battery should read approximately 12.6 volts. Check the battery terminals for corrosion and clean them as necessary. Inspect the wiring harness for any signs of damage, such as frayed wires, loose connections, or corroded terminals. Pay particular attention to areas where the wiring harness is exposed to heat or abrasion. Use a test light or multimeter to check for continuity in the circuits. This can help identify broken wires or open circuits.
If the tractor is experiencing starting problems, check the starter motor circuit. Verify that the starter motor is receiving adequate voltage. Inspect the starter solenoid for proper operation. Check the ignition switch and wiring for any signs of damage or corrosion. If the tractor is not charging properly, check the alternator or generator. Use a multimeter to measure the output voltage of the alternator or generator. A properly functioning alternator or generator should produce approximately 13.5 to 14.5 volts while the engine is running. Inspect the voltage regulator for proper operation.
If lights or other electrical accessories are not working, check the fuses and circuit breakers. Replace any blown fuses or reset any tripped circuit breakers. Use a wiring diagram to trace the circuits and identify the source of the problem. Check the switches and relays associated with the non-functioning accessories. Use a multimeter to test the switches and relays for proper operation. Inspect the grounds for any signs of corrosion or looseness. A poor ground connection can cause a variety of electrical problems.
The John Deere 4255 tractor is equipped with a robust John Deere diesel engine, known for its reliability and power. Specifically, the engine is a six-cylinder, turbocharged, direct-injection diesel. This design ensures efficient combustion and optimal fuel economy, contributing to the tractor's overall productivity. The engine's displacement is approximately 7.6 liters (466 cubic inches), providing ample torque for demanding agricultural tasks. This engine is designed to operate optimally within a specified RPM range, typically between 2200-2400 RPM, allowing for efficient power delivery across a range of operations.
The engine's power output is rated at approximately 130 horsepower at the engine flywheel, allowing for tackling heavy field work such as plowing, tilling, and harvesting. The engine features a 12-volt electrical system for starting and operating various accessories, and is equipped with a heavy-duty air cleaner system to filter out dust and debris, ensuring longevity and consistent performance in harsh environments. The engine also incorporates a pressurized lubrication system, vital for reducing wear and tear on critical components. This system provides a continuous flow of oil to bearings, pistons, and other moving parts, keeping the engine running smoothly.
The John Deere 4255 offers a reliable and versatile transmission system. The transmission is a partial power shift design known as the Quad Range transmission, which provides 16 forward and 8 reverse gears, offering a wide range of speed selections to match various operating conditions. The Quad Range design allows for four powershiftable gears within each range, giving the operator flexibility to make quick adjustments to ground speed on the go, crucial for maintaining efficiency in changing field conditions. These powershiftable gears can be changed on the go without clutching, improving productivity and reducing operator fatigue.
The transmission also includes a differential lock, which can be engaged to provide maximum traction in slippery or challenging terrain. This feature locks both rear wheels together, ensuring that power is delivered equally to both sides, even if one wheel loses traction. This is particularly useful when working on slopes, in muddy fields, or when pulling heavy implements. Regular inspection and maintenance of the transmission are vital for ensuring reliable performance. This includes checking the transmission fluid level and condition, as well as inspecting the gears and bearings for wear.
The hydraulic system on the John Deere 4255 is essential for operating various implements and accessories. It's a closed-center, pressure-compensated system, providing efficient and responsive control. The hydraulic system is designed to deliver a maximum flow rate of approximately 29 gallons per minute (GPM), allowing for quick and efficient operation of hydraulic cylinders and motors. This system ensures that hydraulic power is available when needed, without wasting energy.
The system operates at a working pressure of approximately 2,900 PSI (pounds per square inch). This high pressure allows for lifting heavy loads, operating hydraulic motors, and powering various implements. The tractor is equipped with multiple remote hydraulic outlets, enabling it to be connected to a variety of implements, such as loaders, planters, and harvesting equipment. Routine maintenance of the hydraulic system is crucial for maintaining its performance and reliability. This includes checking the hydraulic fluid level and condition, as well as inspecting the hoses and fittings for leaks.
The electrical system of the John Deere 4255 is designed to provide reliable power for starting the engine and operating various electrical components. It is a 12-volt system, providing power for the starter, lights, instruments, and other electrical accessories. The system includes a battery, an alternator, and a starter motor. The alternator is responsible for charging the battery and providing power to the electrical system while the engine is running.
The system uses a robust wiring harness to connect various electrical components. It is important to periodically inspect the wiring harness for damage and corrosion. The tractor includes various safety features, such as fuses and circuit breakers, to protect the electrical system from overloads and short circuits. These safety devices are designed to interrupt the flow of electricity in the event of a fault, preventing damage to the electrical components. Proper maintenance of the electrical system is essential for ensuring reliable operation of the tractor.
Proper maintenance and repair of your John Deere 4255 tractor often requires specialized tools that aren't typically found in the average home garage. These tools are designed to perform specific tasks safely and efficiently, minimizing the risk of damage to the tractor's components. Using the correct tool is crucial for ensuring that repairs are done right the first time. Ignoring the need for these specialized tools can lead to frustration, potential injury, and costly mistakes. Before undertaking any major repair, consult the service manual to identify the necessary special tools and ensure you have access to them, either through purchase or rental.
John Deere offers a variety of these specialized tools, often available through your local dealership. Examples include clutch alignment tools, fuel injection pump timing tools, and specialized pullers for removing bearings and gears without causing damage. Many aftermarket manufacturers also produce quality alternative options for these tools. When sourcing special tools, always ensure they are designed specifically for the 4255 model to guarantee compatibility and proper function. Consider the long-term investment; a durable, high-quality tool will pay for itself over time by simplifying repairs and preventing component damage.
Accurate measurement is critical for diagnosing problems and ensuring that repaired components meet factory specifications. A basic toolbox should include a high-quality set of metric and standard wrenches, sockets, and screwdrivers. However, when it comes to engine, transmission, and hydraulic repairs, precision measuring instruments are essential. These tools allow you to detect wear, distortion, and other issues that can negatively impact the tractor's performance.
Essential measuring instruments include a precision micrometer set for measuring internal and external dimensions of engine components, a dial indicator for checking runout and alignment, and a torque wrench (discussed further below) for achieving proper fastener torque. A feeler gauge set is indispensable for setting valve clearances and checking bearing endplay. Additionally, a compression tester is vital for diagnosing engine problems related to worn rings or valves. Investing in quality measuring instruments from reputable brands will ensure accuracy and reliability, ultimately saving you time and money in the long run. Calibration is key, ensure that your instruments are calibrated properly.
Proper torque is paramount for the reliable operation of your John Deere 4255. Over-tightening fasteners can lead to thread stripping, component damage, and even catastrophic failure. Conversely, under-tightening can result in loose connections, leaks, and premature wear. The service manual provides detailed torque specifications for all fasteners on the tractor, which should be strictly adhered to during reassembly.
A high-quality torque wrench is an indispensable tool for achieving accurate torque. There are two main types: click-type and beam-type. Click-type torque wrenches are easier to use, as they provide an audible "click" when the desired torque is reached. Beam-type torque wrenches are less expensive but require more visual attention to ensure accuracy. Regardless of the type you choose, always select a torque wrench with a range that covers the torque specifications you'll be working with. It's also crucial to calibrate your torque wrench regularly to maintain accuracy. Remember that torque specifications are typically provided for clean, dry threads. If threads are lubricated, the torque value may need to be adjusted, as specified in the service manual, to avoid over-tightening.
Consistent preventative maintenance is the cornerstone of a long and productive life for your John Deere 4255 tractor. Neglecting routine servicing can lead to costly repairs down the line, reduced performance, and even premature engine failure. This chapter outlines the critical service intervals, lubrication guidelines, and fluid recommendations necessary to keep your 4255 operating at peak efficiency for years to come. By adhering to these recommendations, you'll not only extend the lifespan of your tractor but also maximize its resale value and minimize unexpected downtime during critical farming operations. Remember, a little preventative care goes a long way in ensuring the reliable performance of your valuable investment.
Establishing a regular service schedule is paramount. The intervals outlined here are general guidelines; however, operating conditions and intensity of use may necessitate more frequent servicing. For instance, tractors used in dusty or exceptionally demanding environments should have air filters and lubricants checked and changed more often. Always refer to the instrument panel gauges and indicators for any warning signs that might signal the need for immediate attention. It is crucial to maintain accurate records of all servicing activities, including dates, types of service performed, and the specific products used. These records will be invaluable for future maintenance and troubleshooting.
Daily Checks (Before Each Use): Begin each day by inspecting fluid levels, including engine oil, coolant, hydraulic fluid, and fuel. Look for any visible leaks around seals, hoses, and connections. Examine the tires for proper inflation and any signs of damage or wear. Ensure all lights and indicators are functioning correctly. This brief daily check can prevent minor issues from escalating into major problems during the workday. Don't underestimate the importance of visual inspection; it's the first line of defense against potential mechanical failures.
50-Hour Service: After the initial 50 hours of operation (or every 50 hours thereafter), it's recommended to tighten all bolts and fasteners, especially those on critical components like the engine mounts, transmission, and axle housings. Check the condition of the battery and clean the terminals to ensure proper electrical conductivity. Inspect the air filter for debris and clean or replace it as needed. This service interval helps to ensure that components are properly secured and that the tractor is operating within its optimal parameters. Remember that the initial 50-hour service is especially critical, as components are settling in and adjustments may be required.
250-Hour Service: At 250-hour intervals, change the engine oil and oil filter. Replace the fuel filter to maintain optimal fuel delivery and prevent contaminants from entering the fuel system. Lubricate all grease fittings, including those on the steering linkage, front axle, and other moving parts. Inspect the cooling system hoses for cracks or deterioration and replace them if necessary. Pay close attention to the condition of the belts driving the fan and other accessories; replace them if they show signs of wear or damage. Regular oil and filter changes are crucial for maintaining engine health and prolonging its lifespan.
500-Hour Service: Every 500 hours, change the hydraulic oil and filter. Inspect the transmission oil level and add fluid as needed. Check the condition of the brake pads and adjust them if necessary. Have a qualified technician inspect the injectors and adjust them if needed to optimize fuel efficiency and reduce emissions. Consider having the cooling system flushed and refilled to remove deposits and maintain optimal cooling efficiency. Hydraulic and transmission fluid maintenance is critical for ensuring smooth operation and preventing costly repairs to these systems.
Proper lubrication is absolutely essential to minimizing wear and tear on moving parts. Using the correct type of lubricant for each application is equally important. Refer to the detailed lubrication chart in the operator's manual for specific recommendations. Generally, a high-quality multi-purpose grease is suitable for most grease fittings. However, some applications may require specialized lubricants, such as moly grease for heavily loaded joints. Always clean grease fittings before applying new grease to prevent dirt and debris from being forced into the bearing surfaces. Over-greasing can also be detrimental, so apply grease until it just begins to seep out of the bearing seals.
The following provides a general overview, but **always consult your John Deere 4255 Operator's Manual for the precise grease points and recommended lubricant types.**
Using the correct fluids in your John Deere 4255 is critical for optimal performance and longevity. Always use fluids that meet or exceed the specifications outlined in the operator's manual. Using inferior fluids can lead to premature wear, reduced performance, and even component failure. For engine oil, use a high-quality diesel engine oil with the appropriate API service classification (e.g., CJ-4 or CK-4) and viscosity grade (e.g., 15W-40). For hydraulic fluid, use a John Deere-approved hydraulic fluid or a fluid that meets the John Deere Hy-Gard specification. For coolant, use a 50/50 mixture of ethylene glycol antifreeze and distilled water. Never use tap water, as it can contain minerals that can damage the cooling system.
Here's a summary of common fluid types and important considerations: