This service manual is designed to provide comprehensive information and guidance for the maintenance, repair, and overhaul of John Deere 5-904 series tractors. It is intended for use by qualified technicians and mechanics with a solid understanding of agricultural equipment and internal combustion engines. The manual includes detailed diagrams, schematics, and step-by-step procedures to assist in diagnosing and resolving common issues, as well as performing routine maintenance tasks. It assumes a certain level of familiarity with basic mechanical principles and tool usage. Please consult this manual regularly before and during any repair or maintenance procedure on your John Deere 5-904.
Throughout this manual, you will find information organized by system and component. Each section provides a detailed description of the system, its operation, and the associated components. It also includes troubleshooting charts, diagnostic procedures, and repair instructions. Special attention is given to critical adjustments and tolerances to ensure optimal performance and longevity of your tractor. Be sure to carefully review the safety information section before commencing any work on the tractor. Note that John Deere continually improves its products, so some information may be updated in future revisions. Always refer to the latest available edition of this service manual.
Safety is paramount when working with heavy machinery like the John Deere 5-904. Always wear appropriate personal protective equipment (PPE) such as safety glasses, gloves, and steel-toed boots. Before starting any maintenance or repair procedure, ensure that the tractor is parked on a level surface, the parking brake is engaged, and the engine is switched off and allowed to cool completely. Disconnect the negative terminal of the battery to prevent accidental starting. Never work under a tractor supported only by a jack; always use jack stands of adequate capacity.
Be extremely cautious when working with fluids such as fuel, oil, and coolant. These fluids may be flammable or corrosive, and contact with skin or eyes should be avoided. Always work in a well-ventilated area to prevent the build-up of harmful fumes. When handling fuel, ensure there are no open flames or sources of ignition nearby. Properly dispose of used fluids and parts according to local regulations. Familiarize yourself with the location of fire extinguishers and first aid kits in your workshop. Failure to follow these safety precautions can result in serious injury or even death.
The John Deere 5-904 series tractors are known for their robust construction and dependable performance. These tractors are typically powered by a four-cylinder diesel engine known for its fuel efficiency and torque output. The precise engine specifications, including displacement, horsepower, and torque ratings, will vary depending on the specific model within the 5-904 series. Refer to the tractor's identification plate or the engine's serial number for accurate identification. The transmission is typically a synchronized or partially synchronized manual gearbox offering multiple forward and reverse speeds for a wide range of applications.
The hydraulic system is a critical component of the John Deere 5-904, providing power for implements, steering, and braking. The hydraulic pump delivers pressurized oil to various actuators, allowing for efficient operation of attachments such as loaders, mowers, and plows. The electrical system provides power for starting, lighting, and instrumentation. It typically includes a 12-volt battery, alternator, and starter motor. Specific details about the electrical system, including wiring diagrams and component locations, are provided in subsequent chapters. Regular maintenance and inspection of these key systems are crucial to ensuring the reliable operation and longevity of your John Deere 5-904 tractor.
The heart of your John Deere 5-904 is its engine, a meticulously engineered machine that demands precision during any disassembly or assembly procedure. Before embarking on this task, ensure you have the correct service manual specific to your engine model and serial number. This manual will provide detailed diagrams, torque specifications, and step-by-step instructions crucial for a successful overhaul. A clean, well-lit workspace is also essential, along with a comprehensive set of tools, including torque wrenches, specialized pullers, and measuring instruments. Remember to label and organize all removed parts to prevent confusion during reassembly. This meticulous approach will greatly reduce the chances of error and ensure the engine functions optimally after the rebuild.
Disassembly should proceed in a logical order, carefully documenting each step with photographs or notes. Pay close attention to the condition of all components as you remove them, noting any signs of wear, damage, or corrosion. Worn piston rings, scored cylinder walls, or damaged valve seats will require replacement or reconditioning. Clean all parts thoroughly with appropriate solvents and inspect them closely for cracks or other defects using non-destructive testing methods where applicable. Before reassembly, carefully inspect all bearings for wear and replace them as needed. Proper lubrication during reassembly is crucial; use only the recommended engine oil and apply it liberally to all moving parts.
During assembly, adhering to the torque specifications outlined in the service manual is paramount. Over-tightening can damage components, while under-tightening can lead to leaks or premature failure. Use a calibrated torque wrench and tighten bolts in the specified sequence to ensure even clamping pressure. Pay particular attention to the installation of piston rings, ensuring they are properly staggered and seated correctly. Double-check all clearances and tolerances to ensure they fall within the manufacturer's specifications. Finally, prime the oil pump before starting the engine to ensure adequate lubrication from the outset. A properly disassembled and reassembled engine will provide years of reliable service.
The fuel system is vital for the efficient operation of your John Deere 5-904. Common symptoms of fuel system problems include hard starting, rough idling, loss of power, excessive smoke, and poor fuel economy. A systematic approach to troubleshooting is essential to identify the root cause of the problem. Begin by checking the fuel level and quality. Contaminated fuel can clog filters and injectors, leading to performance issues. Inspect the fuel lines and connections for leaks or restrictions. Air leaks can cause a loss of fuel pressure and prevent the engine from starting or running properly.
Next, examine the fuel filters and replace them if they are clogged or dirty. A restricted fuel filter can starve the engine of fuel, especially under heavy load. Check the fuel pump for proper operation. A faulty fuel pump may not be able to deliver adequate fuel pressure to the injectors. Use a fuel pressure gauge to verify the fuel pressure at the fuel rail. If the fuel pressure is low, inspect the fuel pump relay and wiring harness for any issues. A weak or failing relay can prevent the fuel pump from running at full speed. Also, inspect the fuel tank for debris or rust that could be clogging the fuel pump inlet.
Finally, inspect the fuel injectors for proper operation. Clogged or malfunctioning injectors can cause a variety of performance problems. Use a multimeter to check the injector resistance. An open or shorted injector will need to be replaced. If the injectors are firing but not delivering fuel properly, they may need to be cleaned or replaced. Consider having the injectors professionally cleaned and tested to ensure they are functioning correctly. Regularly inspecting and maintaining the fuel system can prevent costly repairs and ensure the engine runs smoothly and efficiently.
Maintaining the cooling system is crucial to prevent engine overheating and damage. The cooling system is responsible for dissipating excess heat generated by the engine during combustion. Overheating can lead to serious engine problems, such as cracked cylinder heads, blown head gaskets, and piston seizure. Regular inspection and maintenance of the cooling system can help prevent these issues. Begin by checking the coolant level in the radiator and overflow tank. A low coolant level can indicate a leak in the system. Use only the recommended coolant type specified by John Deere to avoid corrosion and damage to the cooling system components.
Inspect the radiator hoses for cracks, leaks, or swelling. Replace any hoses that show signs of wear or damage. Check the radiator cap for proper sealing. A faulty radiator cap can prevent the cooling system from pressurizing properly, leading to overheating. Inspect the radiator fins for debris or obstructions. Clean the radiator fins regularly to ensure adequate airflow. Check the thermostat for proper operation. A malfunctioning thermostat can prevent the engine from reaching its optimal operating temperature or cause it to overheat. Replace the thermostat if it is not functioning correctly.
The water pump is responsible for circulating coolant throughout the engine. Inspect the water pump for leaks or unusual noises. A faulty water pump can cause the engine to overheat. Regularly flush the cooling system to remove sediment and scale buildup. Use a cooling system cleaner to help dissolve deposits and improve cooling system efficiency. By regularly inspecting and maintaining the cooling system, you can ensure the engine operates at its optimal temperature and avoid costly repairs. Remember to dispose of used coolant properly, as it is harmful to the environment.
The lubrication system is essential for reducing friction and wear between moving engine parts. Proper lubrication helps to extend engine life and prevent costly repairs. Regular maintenance of the lubrication system is crucial to ensure it functions correctly. Start by checking the engine oil level regularly. A low oil level can lead to inadequate lubrication and engine damage. Use only the recommended engine oil type specified by John Deere to ensure optimal performance and protection. Change the engine oil and filter at the recommended intervals. Dirty oil can contain abrasive particles that cause wear on engine components.
Inspect the oil filter for any signs of damage or contamination. A clogged oil filter can restrict oil flow and reduce lubrication effectiveness. Check the oil pressure gauge or warning light. Low oil pressure can indicate a problem with the oil pump or a leak in the system. Inspect the oil cooler for leaks or obstructions. A faulty oil cooler can prevent the engine oil from maintaining its optimal temperature. Check the oil pan for leaks or damage. A damaged oil pan can lead to oil loss and engine damage.
The oil pump is responsible for circulating oil throughout the engine. Inspect the oil pump for wear or damage. A faulty oil pump can cause low oil pressure and engine damage. Regularly inspect the lubrication system components for leaks, damage, or wear. Addressing any issues promptly can help prevent costly repairs and ensure the engine operates smoothly and reliably. Remember to properly dispose of used oil and filters, as they are harmful to the environment. Proper lubrication is key to a long and healthy engine life.
Understanding the wiring diagrams for your John Deere 5-904 tractor is crucial for effective troubleshooting and repair. These diagrams provide a roadmap of the entire electrical system, showing the connections between various components like the battery, starter, alternator, lights, sensors, and control units. Familiarize yourself with the symbols and conventions used in the diagrams to accurately trace circuits and identify potential faults. Pay close attention to wire colors and gauge sizes, as these indicate the purpose and current-carrying capacity of each wire. A damaged or corroded wire can lead to voltage drops or complete circuit failures, so understanding the wiring layout is vital for preventative maintenance and quick repairs.
Before working on any electrical component, always disconnect the battery's negative terminal to prevent accidental shorts and potential damage to the system. Refer to the specific wiring diagram that corresponds to your tractor's serial number and model year, as variations may exist. It's also helpful to keep a clean copy of the wiring diagram readily available in the shop, as it can serve as an invaluable resource during complex electrical troubleshooting. Keep in mind that some circuits may include fuses or circuit breakers for protection; knowing their location and purpose is essential for safety and efficient troubleshooting.
The starting system is responsible for cranking the engine until it reaches a speed sufficient for self-sustained combustion. This system typically consists of the battery, starter motor, solenoid, ignition switch, and associated wiring. A common issue is a weak or dead battery, which can prevent the starter from engaging properly. Ensure the battery is fully charged and in good condition, with clean and tight terminals. Corrosion on the terminals can impede current flow, leading to starting problems. Regularly inspect the battery terminals and clean them with a wire brush if necessary, applying a corrosion-inhibiting compound to prevent future buildup.
If the battery is healthy but the starter still fails to engage, the issue may lie with the solenoid or starter motor itself. The solenoid acts as an electrical switch that activates the starter motor when the ignition key is turned. A faulty solenoid can prevent the starter from receiving power, resulting in a no-start condition. The starter motor is a high-torque electric motor that physically cranks the engine. Over time, the brushes inside the starter motor can wear down, leading to reduced performance or complete failure. If the starter motor is suspected, a qualified technician can test its functionality and perform necessary repairs or replacements. Check for loose or corroded wiring connecting the starter to the battery and solenoid, as these can also cause starting issues.
The charging system's primary function is to replenish the battery's energy while the engine is running and to supply electrical power to other components, such as lights and accessories. This system consists primarily of the alternator, voltage regulator, and associated wiring. The alternator converts mechanical energy from the engine into electrical energy. The voltage regulator maintains a constant voltage output from the alternator to prevent overcharging and damage to the battery and other electrical components. A malfunctioning charging system can lead to a discharged battery, causing starting problems and affecting the operation of other electrical systems. Regularly check the battery voltage with a multimeter to ensure the charging system is functioning correctly.
Inspect the alternator belt for wear or damage, as a slipping belt can reduce the alternator's output. Also, check the wiring connections to the alternator and voltage regulator for corrosion or loose connections. A faulty voltage regulator can cause overcharging, which can damage the battery, or undercharging, which can lead to a discharged battery. If the charging system is suspected of malfunctioning, a qualified technician can perform tests on the alternator and voltage regulator to determine the cause of the problem. Replacing worn brushes, diodes, or other internal components can often restore the alternator to proper working order. Ensure proper grounding of the alternator and voltage regulator, as this is critical for the charging system's efficiency.
The lighting and instrumentation systems are essential for safe operation and monitoring of the tractor's performance. These systems include headlights, taillights, turn signals, dashboard gauges, and warning lights. Properly functioning lights are crucial for visibility during nighttime operation and in poor weather conditions. Regularly inspect the headlights and taillights to ensure they are working correctly. Replace any burnt-out bulbs immediately to maintain visibility and safety. Check the wiring and connectors for corrosion or damage, as these can cause intermittent lighting problems. Inspect the lenses of the lights for cracks or damage, as these can reduce their effectiveness.
Dashboard gauges provide critical information about the tractor's engine, such as oil pressure, coolant temperature, and fuel level. Warning lights alert the operator to potential problems, such as low oil pressure or overheating. If any gauges are not functioning correctly or warning lights are illuminated, investigate the cause immediately. Faulty sensors, wiring problems, or instrument panel issues can lead to inaccurate readings. Consult the wiring diagrams to trace the circuits and identify the source of the problem. Replacing faulty sensors or repairing wiring issues can often restore the gauges to proper working order. Calibrating the gauges may also be necessary to ensure accurate readings.
The clutch in your John Deere 5-904 is a critical component, responsible for transferring power from the engine to the transmission. Proper clutch operation is essential for smooth shifting and efficient performance. Over time, the clutch disc can wear, the pressure plate can weaken, and the release bearing can become noisy or seize. Recognizing the signs of a failing clutch is crucial to prevent further damage and costly repairs. Some common symptoms include slippage (engine revving without proportional acceleration), difficulty shifting gears, unusual noises during clutch engagement or disengagement, and a "dragging" clutch (difficulty coming to a complete stop even with the clutch pedal fully depressed).
Before beginning any clutch service, always disconnect the battery to prevent accidental starting and potential injury. Start by carefully removing the tractor hood and any necessary side panels to gain access to the clutch housing. Depending on the specific model variation, you may need to remove other components, such as the fuel tank or operator's platform, to provide adequate clearance. Thoroughly clean the clutch housing area with a degreaser to remove any dirt, grease, and debris that could contaminate the clutch components. Proper preparation is key to a successful clutch service. Ensure you have the appropriate tools and replacement parts, including a new clutch disc, pressure plate, release bearing, and pilot bearing, as needed.
Once you have access, carefully inspect the clutch components for wear, damage, or contamination. Check the clutch disc for excessive wear, oil contamination, or broken friction material. Inspect the pressure plate for cracks, warping, or worn-out release fingers. Examine the release bearing for smooth rotation and any signs of damage or wear. Replace any components that are worn or damaged. When installing the new clutch disc, ensure it is properly aligned with the pilot bearing using a clutch alignment tool. Tighten the pressure plate bolts in a star pattern to the specified torque to ensure even pressure distribution and prevent distortion. A properly installed clutch is critical for optimal performance and longevity.
The transmission is the heart of your tractor's power train, responsible for providing the various gear ratios needed for different operating conditions. Over time, transmission components can wear, leading to shifting problems, noise, and reduced performance. Recognizing the signs of a failing transmission is important to prevent catastrophic failure. Common symptoms include difficulty shifting gears, grinding noises during shifting, slipping out of gear, and excessive noise or vibration from the transmission housing. Ignoring these symptoms can lead to more significant damage and costly repairs.
A complete transmission overhaul is a complex procedure that requires specialized tools and knowledge. Before beginning, consult the service manual for your specific model and follow the instructions carefully. It is crucial to have a clean and organized workspace to prevent contamination of the transmission components. Begin by draining the transmission oil and carefully removing the transmission housing. Take pictures or make detailed notes of the location of each component as you disassemble the transmission. This will help ensure proper reassembly. A parts diagram will also be invaluable for proper assembly.
Once the transmission is disassembled, thoroughly inspect each component for wear, damage, or breakage. Check the gears for chipped teeth, excessive wear, or pitting. Inspect the bearings for smooth rotation and any signs of damage or wear. Examine the shafts for bending, cracking, or excessive wear. Replace any components that are worn or damaged. Before reassembling the transmission, thoroughly clean all components with a solvent and inspect the transmission housing for cracks or damage. Apply fresh lubricant to all moving parts during reassembly. Ensure all gears, bearings, and shafts are properly aligned and installed. Tighten all bolts to the specified torque. After reassembly, fill the transmission with the correct type and amount of transmission oil. Verify proper operation by testing all gears for smooth shifting and proper engagement.
The differential and final drive are essential components of the tractor's power train, responsible for transferring power from the transmission to the wheels. The differential allows the wheels to rotate at different speeds when turning, while the final drive provides the necessary gear reduction to deliver high torque to the wheels. These components are subjected to high loads and stresses, so proper maintenance is essential for reliable operation. Failure to properly maintain the differential and final drive can result in costly repairs.
Regularly inspect the differential and final drive for leaks, unusual noises, or vibration. Check the oil level in the differential and final drive housings and top off as needed. Change the oil according to the manufacturer's recommendations. When changing the oil, inspect the old oil for metal particles or other contaminants, which could indicate wear or damage. If you notice any leaks, repair them promptly to prevent further damage. A thorough inspection during maintenance can prevent costly repairs down the line.
Over time, the bearings, gears, and other components in the differential and final drive can wear, leading to noise, vibration, and reduced performance. If you suspect a problem with the differential or final drive, it is important to diagnose the problem and make the necessary repairs as soon as possible. This may involve disassembling the differential or final drive to inspect the components for wear or damage. Replace any worn or damaged components, and reassemble the differential or final drive according to the manufacturer's instructions. Always use the correct torque specifications when tightening bolts and fasteners. Proper maintenance and timely repairs will help ensure the long and reliable operation of your tractor's differential and final drive.
The Power Take-Off (PTO) system is a vital component of your John Deere 5-904, providing the power needed to operate implements such as mowers, tillers, and balers. Proper PTO system maintenance is crucial for safe and efficient operation. A malfunctioning PTO can lead to implement damage, personal injury, or even catastrophic tractor failure. Always adhere to the manufacturer's safety guidelines when operating PTO-powered equipment. This includes ensuring that all guards are in place and that the PTO shaft is properly connected and secured.
Regularly inspect the PTO shaft and driveline for wear, damage, or missing components. Check the universal joints for play and lubricate them regularly. Inspect the PTO shield for damage and replace it if necessary. Ensure that the PTO driveline is properly aligned to prevent excessive vibration and wear. Before engaging the PTO, make sure that the implement is properly attached and that all safety interlocks are functioning correctly. Always disengage the PTO before dismounting the tractor or performing maintenance on the implement. Proper maintenance and safe operating practices are essential for preventing accidents and ensuring the long and reliable operation of your PTO system.
The PTO clutch is another critical component that requires periodic maintenance. Check the clutch for proper engagement and disengagement. Adjust the clutch linkage as needed to ensure smooth operation. If the PTO clutch is slipping or failing to engage, it may need to be repaired or replaced. Consult the service manual for your specific model for instructions on how to service the PTO clutch. Proper lubrication is also essential for the PTO system. Lubricate the PTO shaft, bearings, and other moving parts according to the manufacturer's recommendations. A well-maintained PTO system will provide years of reliable service and help you get the most out of your tractor.
The hydraulic pump is the heart of your John Deere 5-904's hydraulic system, responsible for generating the necessary pressure to operate various implements and accessories. Regular servicing of the hydraulic pump is crucial for maintaining optimal performance and preventing costly downtime. This involves inspecting the pump for leaks, checking the fluid level and condition, and ensuring that all connections are secure. Failure to properly maintain the pump can lead to decreased hydraulic power, erratic operation of implements, and ultimately, pump failure. Always consult the manufacturer's specifications and use genuine John Deere parts when performing any maintenance or repairs on the hydraulic pump.
Before beginning any service on the hydraulic pump, it's essential to relieve the pressure in the hydraulic system. This can be achieved by lowering all implements to the ground and shutting off the tractor engine. Disconnect the battery to prevent accidental starting during the service procedure. Carefully inspect the pump housing for any signs of cracks, leaks, or damage. Check the condition of the drive shaft and coupling, ensuring that they are properly aligned and securely fastened. If any damage is found, replace the affected components with genuine John Deere parts to maintain the integrity and reliability of the hydraulic system.
The hydraulic fluid itself plays a critical role in the pump's longevity and performance. Regularly check the fluid level and condition, and change the fluid according to the recommended service intervals outlined in the operator's manual. Contaminated or degraded hydraulic fluid can cause excessive wear on the pump's internal components, leading to reduced efficiency and eventual failure. When adding or replacing hydraulic fluid, always use the correct type and grade specified by John Deere. Following these simple steps can significantly extend the life of your hydraulic pump and ensure smooth and reliable operation of your tractor.
The control valves in the hydraulic system regulate the flow of hydraulic fluid to various implements, allowing you to control their movement and operation. Proper adjustment of the control valves is essential for ensuring smooth and precise operation of these implements. If the control valves are not properly adjusted, you may experience jerky movements, slow response times, or difficulty controlling the implements at all. These issues not only impact the efficiency of your work but can also pose safety hazards. Therefore, routine checks and adjustments of the control valves are a critical part of maintaining your John Deere 5-904's hydraulic system.
To adjust the control valves, first, consult the service manual for the specific procedures and specifications for your tractor model. The adjustment process typically involves loosening locknuts and turning adjusting screws to fine-tune the valve's response. Pay close attention to the position of the control lever and the corresponding movement of the implement. Make small adjustments and test the operation of the implement after each adjustment to ensure that it responds smoothly and accurately. Remember to tighten the locknuts securely after completing the adjustment to prevent the screws from drifting out of position.
If you're unsure about the correct adjustment procedure or if you suspect that the control valves are worn or damaged, it's best to consult a qualified John Deere technician. Incorrect adjustments can cause further damage to the hydraulic system and could potentially lead to accidents. Regular maintenance and timely repairs performed by a trained professional will help ensure that your control valves operate correctly and that your hydraulic system remains reliable and efficient. They have the special tools and experience to complete this task in a safe and effective manner.
Hydraulic cylinders are responsible for converting hydraulic pressure into linear motion, powering a wide range of implements on your John Deere 5-904. These cylinders are subject to heavy use and wear, so regular inspection and repair are essential for maintaining proper operation. Common issues with hydraulic cylinders include leaks, bent rods, damaged seals, and worn bushings. Ignoring these problems can lead to reduced hydraulic power, jerky movements, and ultimately, complete cylinder failure. Prompt repair of hydraulic cylinders can prevent further damage and ensure the reliable operation of your tractor.
Before attempting any repairs, always relieve the pressure in the hydraulic system and disconnect the cylinder from the hydraulic lines. Thoroughly clean the cylinder to remove any dirt or debris. Carefully inspect the cylinder rod for any signs of bending, scratches, or corrosion. Check the condition of the seals and wipers, looking for cracks, tears, or wear. If any damage is found, replace the affected components with genuine John Deere parts. Pay close attention to the proper installation of the seals and wipers to prevent leaks. Using the correct tools and techniques is critical for ensuring a successful repair.
When reassembling the hydraulic cylinder, be sure to lubricate all moving parts with hydraulic fluid to ensure smooth operation. Tighten all fasteners to the specified torque. After reinstallation, carefully bleed the hydraulic system to remove any trapped air. Test the cylinder's operation under load to verify that it functions correctly and that there are no leaks. Regular maintenance and timely repairs of your hydraulic cylinders will help extend their lifespan and ensure the reliable operation of your John Deere 5-904.
Diagnosing hydraulic issues can be challenging, but with a systematic approach, you can often pinpoint the problem and take corrective action. Start by observing the symptoms carefully. Is the hydraulic system slow to respond? Are there any unusual noises? Are any implements not functioning correctly? Gather as much information as possible before attempting any repairs. This will help you narrow down the potential causes and avoid unnecessary work.
Begin by checking the basics. Verify that the hydraulic fluid level is correct and that the fluid is clean and free of contaminants. Inspect all hydraulic lines and fittings for leaks. Check the condition of the hydraulic filter and replace it if necessary. Examine the hydraulic pump for any signs of damage or wear. If you suspect a problem with the control valves, test their operation individually. Use a pressure gauge to check the hydraulic pressure at various points in the system to identify any restrictions or pressure drops.
If you're unable to diagnose the problem yourself, consult the service manual or seek assistance from a qualified John Deere technician. They have the knowledge, experience, and specialized tools necessary to troubleshoot complex hydraulic issues and perform the necessary repairs. Remember to always prioritize safety when working on hydraulic systems. Relieve the pressure before disconnecting any lines or components, and wear appropriate personal protective equipment.
The steering system is a critical safety component of your John Deere 5-904. Regular inspection is paramount to ensure proper function and prevent accidents. Begin by visually inspecting all steering linkage components, including tie rod ends, drag links, and steering arms, for signs of wear, damage, or looseness. Pay close attention to any play or excessive movement in these connections. A thorough visual assessment should also include a check of the power steering pump and hydraulic lines for leaks or damage. Any identified issues should be addressed promptly to maintain optimal steering performance and prevent potential hazards.
Next, evaluate the steering wheel play. Excessive free play indicates wear in the steering system components, potentially affecting steering responsiveness and accuracy. To check this, start the engine and allow the power steering system to reach operating pressure. Gently rock the steering wheel back and forth within the free play zone, noting the amount of movement before the front wheels begin to turn. Compare the measured free play against the manufacturer's specifications outlined in this manual. Exceeding the maximum allowable free play warrants further investigation and potential component replacement.
Finally, inspect the power steering fluid level and condition. Low fluid levels can indicate leaks in the system, leading to reduced power steering assist and potentially damaging the pump. Check the fluid level in the reservoir, ensuring it falls within the marked range. The fluid should also be clean and free of contaminants. Dark or milky fluid suggests contamination, necessitating a fluid flush and potential system inspection. Replacing the fluid according to the recommended service intervals is a crucial aspect of preventive maintenance for the steering system.
Repairing the brake system of a John Deere 5-904 requires meticulous attention to detail and adherence to proper safety procedures. Before initiating any repair work, ensure the tractor is safely secured with the parking brake engaged and wheels chocked. Disconnect the battery to prevent accidental electrical activation. Always use appropriate personal protective equipment (PPE), including safety glasses and gloves. Familiarize yourself with the specific braking system components on your tractor model, referencing the diagrams and schematics provided in this manual.
When servicing brake pads or shoes, carefully inspect the condition of the brake rotors or drums. Look for signs of wear, scoring, or warping. Measure the thickness of the rotors or drums to ensure they meet the minimum specified thickness. Worn or damaged rotors/drums can significantly reduce braking performance and should be replaced immediately. When replacing brake pads or shoes, ensure they are properly seated and aligned within the calipers or brake assemblies. Improper installation can lead to uneven wear, noise, and reduced braking effectiveness.
Bleeding the brake system is a critical step following any repair that involves opening the hydraulic lines. Air trapped in the brake lines can compress, resulting in a spongy brake pedal and diminished braking power. Use the correct bleeding procedure for your tractor model, starting at the wheel furthest from the master cylinder and working your way closer. Continuously monitor the fluid level in the master cylinder during the bleeding process, ensuring it does not drop too low. Bleeding should be performed until all air bubbles are eliminated from the brake lines, resulting in a firm and responsive brake pedal.
Proper wheel alignment is crucial for optimal tire wear, fuel efficiency, and steering stability of your John Deere 5-904. Misalignment can lead to premature tire wear, increased fuel consumption, and difficulty maintaining a straight course. Before performing any alignment adjustments, ensure the tires are properly inflated to the recommended pressure. Inspect the steering linkage for any excessive play or damage, addressing any issues before proceeding with the alignment process. Always consult the manufacturer's specifications for the correct alignment settings for your tractor model.
Toe-in is a critical alignment parameter that refers to the difference in distance between the front of the tires and the rear of the tires. Correct toe-in ensures the tires track properly and minimizes tire wear. Use a precision measuring tool, such as a toe-in gauge, to accurately measure the toe-in. Adjust the tie rod ends to achieve the specified toe-in value. After making adjustments, double-check the toe-in measurement to ensure it is within the acceptable range. An incorrect toe-in setting can cause rapid tire wear and compromise steering performance.
Caster and camber are additional alignment angles that affect steering stability and tire wear. Caster refers to the angle of the steering pivot axis relative to the vertical, while camber refers to the angle of the wheel relative to the vertical. Adjusting caster and camber requires specialized equipment and expertise. If you suspect caster or camber issues, it is recommended to consult a qualified technician with experience in agricultural equipment alignment. Improperly adjusted caster or camber can lead to handling problems and uneven tire wear.
The John Deere 5-904 is often equipped with a front-end loader, significantly enhancing its versatility. Proper loader maintenance is crucial for safe and efficient operation. Regularly inspect all hydraulic lines and fittings for leaks. Any signs of weeping or damage should be addressed immediately to prevent catastrophic failure and potential injury. Furthermore, ensure the loader frame and bucket are free from cracks or deformation. These structural components are subjected to immense stress during operation, and any weakening could lead to dangerous situations. Pay close attention to the pivot points and lubrication fittings, applying grease as specified in the service schedule.
Hydraulic cylinder maintenance is another vital aspect of loader upkeep. Inspect the cylinder rods for nicks, scratches, or rust. These imperfections can damage the seals and lead to hydraulic fluid leakage. If damage is found, the rods should be professionally repaired or replaced. Periodically check the cylinder mounting points for wear and tightness. Loose or worn mounting points can cause excessive play and stress on the cylinders, reducing their lifespan and potentially compromising the loader's stability. Additionally, ensure the hydraulic oil level in the tractor's reservoir is maintained at the correct level.
Maintaining the mower deck on your John Deere 5-904 is paramount for achieving a clean, even cut and prolonging the life of the equipment. Before each mowing session, visually inspect the blades for sharpness, damage, or imbalance. Dull blades tear the grass, leaving it vulnerable to disease and resulting in an uneven cut. Damaged or imbalanced blades can cause excessive vibration, leading to premature wear on the deck components and potentially creating a safety hazard. Sharpen or replace blades as needed, always ensuring that they are properly balanced before installation.
The mower deck's spindles and bearings require regular lubrication to ensure smooth operation and prevent premature failure. Consult the service manual for the recommended lubrication intervals and the appropriate type of grease. Over-greasing can be as detrimental as under-greasing, so adhere to the manufacturer's specifications. Furthermore, inspect the deck's belts for cracks, fraying, or excessive wear. Worn belts can slip, reducing cutting efficiency and potentially causing damage to the deck's drive system. Replace worn belts with genuine John Deere parts to ensure proper fit and performance. Finally, ensure the deck is properly leveled to achieve an even cut across the entire width of the mower.
The hitch system on the John Deere 5-904 is designed to connect the tractor to implements. Proper maintenance and repair are essential for safe and effective operation. Regularly inspect the hitch components for wear, damage, or corrosion. Pay close attention to the hitch pins, clevises, and linkages, as these are subjected to significant stress during operation. Replace any worn or damaged parts immediately to prevent implement detachment and potential accidents. Furthermore, ensure the hitch locking mechanisms are functioning correctly and securely engage the implement.
The hydraulic lift system, if equipped, requires careful attention. Check the hydraulic lines and cylinders for leaks or damage. Address any issues promptly to maintain consistent lifting power. Lubricate the hitch pivot points and linkages as specified in the service manual to ensure smooth operation and prevent premature wear. Inspect the sway chains or bars for proper adjustment and condition. These components prevent the implement from swaying excessively during operation, maintaining stability and control. If the tractor is fitted with a three-point hitch, inspect the adjustable links and levelers to ensure the implement is properly aligned and level.
Diagnosing problems with your John Deere 5-904 tractor requires a systematic approach. Before diving into specific components, always start with the basics. Begin by visually inspecting the entire tractor for any obvious signs of damage, leaks, or loose connections. Check fluid levels, including engine oil, coolant, hydraulic fluid, and transmission oil. Ensure the battery is properly charged and the terminals are clean and secure. A simple visual check can often reveal the root cause of the problem or at least narrow down the potential areas of concern. Ignoring these initial steps can lead to wasted time and effort disassembling components that are not actually faulty.
Once the initial visual inspection is complete, start the tractor and listen carefully for any unusual noises. These noises can provide valuable clues about the location and nature of the problem. Pay attention to engine knocking, hissing sounds, grinding noises, or any other sounds that are not normally present during operation. Compare the current running condition to its normal state. Also, if present, review the diagnostic error codes being displayed. Use a stethoscope or a long screwdriver to pinpoint the source of noises more accurately, taking care to avoid moving parts.
Next, systematically test each system of the tractor, starting with the easiest and most common problems. Check the fuel system for proper flow and pressure. Ensure the air intake system is free from obstructions. Inspect the electrical system for shorts, open circuits, or faulty sensors. If the tractor is experiencing hydraulic issues, test the hydraulic pump and valves for proper function. Don't overlook potential electrical problems and review the wiring and grounds for corrosion. Remember to consult the wiring schematics in this manual for assistance in tracing electrical circuits.
If your engine is refusing to start, you should focus on the engine and fuel components. Firstly, check that the fuel tank has adequate fuel and make sure that the fuel shut-off valve is in the open position. Next, inspect the fuel filter for clogs or contaminants and replace it if necessary. Also, check the condition and connections of your battery to ensure you have ample electricity to spark and power the engine. If the electrical connections are secure, then use a multimeter to test the output of the battery and the voltage running to the components. After these checks are complete, inspect the ignition system, spark plugs, and coils to check for damage or wear.
Overheating can cause significant damage to your engine if not addressed promptly. Start by checking the coolant level in the radiator and overflow tank. Low coolant is a common cause of overheating. Next, inspect the radiator for obstructions, such as dirt, debris, or bent fins. Use a garden hose or compressed air to clean the radiator core thoroughly. Ensure the thermostat is functioning properly. A faulty thermostat can restrict coolant flow and cause the engine to overheat. A water pump that is damaged or malfunctioning can be the cause of overheating. Check the fan and fan belt to see if they are running normally and providing the correct amount of airflow.
Hydraulic system malfunctions are usually easily pinpointed. Hydraulic systems should first be inspected for leaks in hoses or seals. Next, check the hydraulic fluid level in the reservoir and add fluid as needed. Ensure the hydraulic filter is clean and replace it if necessary. A clogged filter can restrict fluid flow and cause the hydraulic system to perform poorly. If your tractor has a hydraulic pump, test its pressure output to ensure it is meeting the manufacturer's specifications. If the pressure is low, the pump may need to be repaired or replaced.
Proper torque is absolutely crucial when assembling or repairing any component on your John Deere 5-904 tractor. Using incorrect torque values can lead to premature wear, component failure, and even dangerous operating conditions. Always consult the specific torque specifications listed in this section for each fastener size and application. Remember to clean the threads of both the bolt and the receiving component before applying torque. This ensures an accurate reading and prevents contaminants from affecting the clamping force. If a specific torque value is not listed, use the general torque chart provided, taking into account the fastener size, material, and thread pitch. It's always better to double-check and confirm than to risk damaging critical parts with improper tightening.
When using a torque wrench, ensure it is properly calibrated and functioning correctly. Regularly check the calibration of your torque wrench, especially if it has been dropped or subjected to heavy use. The torque values provided in this manual are based on dry threads. If lubrication is necessary or recommended for a specific fastener, adjust the torque value accordingly, typically reducing it by 15-20%. Overtightening is just as detrimental as undertightening. Over-torqued fasteners can stretch, weaken, or even break, leading to serious problems down the line. Therefore, adhere strictly to the specified torque values to maintain the integrity and reliability of your tractor.
Selecting the correct lubricants is vital for the longevity and optimal performance of your John Deere 5-904. John Deere's Hy-Gard transmission and hydraulic oil is highly recommended for the transmission, hydraulic system, and wet brakes. Using an inferior or incompatible fluid can cause damage to these critical components. Always consult the lubricant chart to determine the correct oil viscosity for the operating temperature range in your region. Consider the ambient temperature when choosing between different oil grades. Higher viscosity oils are generally preferred for warmer climates, while lower viscosity oils are better suited for colder conditions.
For the engine, John Deere's Plus-50 II engine oil is the preferred choice, offering excellent protection against wear and corrosion. Regularly check the oil level and change the oil and filter according to the recommended service intervals. The use of appropriate grease, such as John Deere's Multi-Purpose SD Polyurea Grease, is essential for lubricating bearings, joints, and other moving parts. Greasing intervals should be carefully observed to prevent wear and ensure smooth operation. Avoid mixing different types of greases as they might not be compatible and could lead to lubrication failure. Always follow the manufacturer's recommendations for lubricant types and service intervals.
Certain repairs and maintenance procedures on the John Deere 5-904 may require the use of specialized tools. These tools are designed to simplify complex tasks, ensure proper alignment, and prevent damage to components. This section outlines the special tools that are commonly used when servicing this model. One common special tool is the bearing puller, used to remove bearings without damaging the bearing housing or the bearing itself. It is critical that the correct size puller be used.
Another vital tool is the injection pump timing tool, which is essential for accurately setting the timing of the fuel injection system. Using the wrong timing tool could result in poor engine performance and increased fuel consumption. Special adapters or sockets may also be required for specific fasteners that are not accessible with standard tools. Always consult the service procedure before attempting any repair to determine if special tools are needed. Using the correct tool for the job will save time, prevent frustration, and ensure that the repair is done correctly. A list of suppliers where the tools may be purchased may be found online.
Throughout this service manual, various units of measurement are used, including metric and imperial units. This section provides conversion charts to assist you in converting between these different units. Accurate conversions are crucial when working with torque specifications, fluid volumes, and other measurements. Using the wrong units can lead to significant errors and potential damage. Pay close attention to the units specified in the manual and use these charts to convert them accurately.
These conversion charts include conversions for length (inches to millimeters), weight (pounds to kilograms), torque (foot-pounds to Newton-meters), and fluid volume (gallons to liters). Always double-check your conversions to ensure accuracy. It is also good practice to confirm your conversions using online conversion tools, but always rely on the charts provided for ultimate precision. Remember that accurate measurements and conversions are essential for proper maintenance and repair of your John Deere 5-904 tractor and this appendix is provided to make this easier to achieve. The chart can assist in ordering the right materials from any manufacturer.