The John Deere 790 is a compact utility tractor designed for a variety of tasks, from mowing and landscaping to light agricultural work. This robust machine is celebrated for its reliability, ease of operation, and versatility in handling different implements. Knowing the specific capabilities and limitations of your 790 is crucial for efficient and safe operation. It’s important to familiarize yourself with the key components, controls, and performance specifications. By understanding these core elements, you can ensure your tractor operates at peak performance for years to come.
The John Deere 790 typically features a Yanmar diesel engine, known for its durability and fuel efficiency. Key specifications include the engine horsepower, which influences the tractor's pulling and lifting capacity, and the PTO (Power Take-Off) horsepower, which dictates the capabilities of implements powered by the tractor. Understanding the hydraulic system's flow rate and pressure is vital for operating loaders, backhoes, and other hydraulically powered attachments. Refer to the detailed specification sheet in your manual for exact figures pertinent to your specific model and configuration. Understanding the specific configuration and specifications of your tractor is vital to safe operation.
The transmission on the John Deere 790 is usually a manual gear transmission, often offering a range of forward and reverse speeds. Proper shifting and gear selection are fundamental to maximizing the tractor's performance and preventing undue stress on the drivetrain. Be sure to consult the gear selection chart provided in this manual, considering the load, terrain, and intended task. The tractor's dimensions, weight, and tire size all play significant roles in its stability and maneuverability. These factors should be considered when operating on uneven terrain or in confined spaces.
Operating any tractor involves inherent risks, and the John Deere 790 is no exception. Adhering to strict safety precautions is paramount to prevent accidents and injuries. Always start by thoroughly reading and understanding the entire operator's manual, paying close attention to the warnings and cautions sections. Ensure that all operators are properly trained and familiar with the tractor's controls and safety features before operating the machine. Never allow untrained individuals to operate the tractor. Safety is the most important aspect of operating any piece of machinery.
Before starting the engine, perform a walk-around inspection to check for any loose parts, leaks, or other potential hazards. Verify that all guards and shields are in place and in good working condition. Confirm that the tires are properly inflated and that the brakes are functioning correctly. Keep the area around the tractor clear of obstructions and bystanders, especially children. Never attempt to operate the tractor under the influence of alcohol or drugs. Never allow riders on the tractor if it is not equipped with a passenger seat.
When operating the tractor on slopes or uneven terrain, exercise extreme caution to prevent rollovers. Always wear a seatbelt and, if equipped, ensure the ROPS (Rollover Protective Structure) is in the upright and locked position. Avoid making sudden turns or abrupt stops on slopes. Be mindful of overhead obstacles such as power lines and tree branches. When transporting the tractor on public roads, adhere to all traffic laws and regulations. Use appropriate warning lights and reflectors to ensure visibility to other vehicles. Safe operation should always be the first concern when operating heavy equipment.
Before you even think about turning the key of your John Deere 790, a thorough pre-operation check is paramount. This isn't just a formality; it's a critical step in ensuring your safety and the longevity of your machine. Neglecting these checks can lead to unexpected breakdowns in the field, costly repairs, and even dangerous situations. Begin by visually inspecting the tractor for any signs of damage, leaks, or loose parts. Pay close attention to the tires, ensuring they are properly inflated and free from cuts or bulges.
Next, delve into the mechanical aspects. Check the engine oil level using the dipstick, adding more if necessary to reach the full mark. Examine the coolant level in the radiator, making sure it's within the recommended range. Insufficient coolant can lead to overheating and engine damage, so this step is crucial. Also, ensure the air filter is clean, as a dirty filter restricts airflow and reduces engine performance. These are all critical things to check on the John Deere 790.
Don't forget to inspect the hydraulic system. Check the hydraulic fluid level and look for any leaks in the lines or cylinders. Low hydraulic fluid can affect the tractor's ability to lift implements or operate its attachments. Finally, verify that all lights, including headlights, taillights, and turn signals, are functioning properly. A well-lit tractor is essential for safe operation, especially in low-light conditions. By diligently performing these pre-operation checks, you'll significantly reduce the risk of accidents and ensure your John Deere 790 is ready to tackle any task.
Starting your John Deere 790 should be a deliberate process, not a rushed one. First, ensure the transmission is in neutral and the parking brake is engaged. This prevents the tractor from moving unexpectedly when the engine starts. Insert the key into the ignition switch and turn it to the "on" position. This allows the electrical system to power up and prepare the engine for ignition. Wait a few seconds for the glow plugs (if equipped) to heat up, especially in cold weather. Glow plugs are essential for pre-heating the engine cylinders, allowing for easier start-up.
Once the glow plugs have warmed up (usually indicated by a light going off or a timer), turn the key to the "start" position. Hold the key in this position until the engine starts. Avoid grinding the starter by releasing the key as soon as the engine fires up. Allow the engine to idle for a few minutes to warm up before putting it under load. This allows the oil to circulate properly and lubricate all engine components, reducing wear and tear. Do not start the engine in an enclosed location.
Stopping the engine is just as important as starting it. Release the throttle and allow the engine to idle for a few minutes to cool down. This helps prevent heat soak and extends the life of the engine components. Turn the key to the "off" position to shut down the engine. If the tractor is equipped with a turbocharger, it's even more crucial to let it cool down before shutting off the engine. Turbochargers operate at extremely high temperatures, and abruptly shutting off the engine can cause oil to coke up inside the turbocharger, leading to premature failure. Once the engine has stopped, remove the key from the ignition switch for added safety.
Familiarizing yourself with the controls and instruments of your John Deere 790 is fundamental for safe and efficient operation. The steering wheel controls the direction of the tractor, while the throttle controls the engine speed. Use the throttle to adjust the power output of the engine according to the task at hand. The transmission lever selects the gear you're operating in, controlling both speed and power. Understanding the gear ratios is crucial for optimizing performance and preventing engine strain.
The hydraulic levers control the operation of implements such as loaders, mowers, and plows. Be sure to familiarize yourself with each lever and its corresponding function before operating any attachments. The instrument panel provides vital information about the tractor's performance. This typically includes gauges for engine temperature, oil pressure, fuel level, and battery voltage. Monitoring these gauges regularly allows you to detect potential problems early and prevent serious damage.
Pay close attention to any warning lights that may illuminate on the instrument panel. These lights indicate specific issues that require immediate attention. Consult your owner's manual to understand the meaning of each warning light and take appropriate action. Properly understanding and utilizing the controls and instruments ensures safe operation and allows you to get the most out of your John Deere 790.
Mastering proper driving and operating techniques is essential for safe and productive use of your John Deere 790. Always wear your seatbelt, as it's your primary protection in case of an accident. Before starting to move, ensure that the area is clear of obstacles and bystanders. Always maintain a safe speed, especially when operating on uneven terrain or slopes. Excessive speed can lead to loss of control and rollovers.
When operating on hills, drive straight up or down the slope whenever possible. Avoid turning across the slope, as this can increase the risk of a rollover. Use the brakes to control your speed when descending a hill. Select a low gear to provide engine braking and prevent the tractor from accelerating out of control. When turning, reduce your speed and use smooth, controlled movements of the steering wheel.
Be mindful of the turning radius of the tractor, especially when operating in confined spaces. Avoid sharp turns that can damage the tires or stress the steering system. When operating with implements, always follow the manufacturer's instructions and safety guidelines. Ensure that the implement is properly attached and adjusted before starting to work. Regularly inspect the implement for any signs of wear or damage and make necessary repairs or replacements. By practicing safe driving and operating techniques, you can minimize the risk of accidents and ensure a long and productive life for your John Deere 790.
Adhering to a regular maintenance schedule is paramount to ensuring the longevity and optimal performance of your John Deere 790. Skipping routine tasks can lead to premature wear and tear, costly repairs, and reduced efficiency. The recommended maintenance schedule can be found in the comprehensive maintenance chart provided in this manual. Always consult the chart before undertaking any maintenance procedure. This schedule outlines the frequency of various tasks, such as lubrication, fluid checks, and filter replacements, based on operating hours. Make sure you understand what the schedule entails.
Before starting any maintenance task, always ensure the tractor is parked on a level surface, the engine is shut off and cooled down, and the parking brake is engaged. Disconnect the negative (-) battery cable to prevent accidental starting. Assemble all necessary tools and supplies beforehand to streamline the process and minimize downtime. Read the entire maintenance procedure outlined in this chapter before you begin. Having everything ready and understanding the scope will make the maintenance tasks much easier.
Regularly inspect the tractor for any signs of leaks, damage, or unusual wear. Pay close attention to hoses, belts, tires, and connections. Address any issues promptly to prevent them from escalating into major problems. Maintaining a clean tractor is also essential. Regularly wash the tractor to remove dirt, mud, and debris that can accelerate corrosion and wear. A clean tractor also makes it easier to identify potential problems during visual inspections. Consider pressure washing your tractor every so often, to remove any dirt and grime.
Proper lubrication is critical to minimizing friction, preventing wear, and extending the life of moving parts on your John Deere 790. Insufficient lubrication can lead to overheating, premature failure of components, and reduced overall performance. Refer to the lubrication chart in this manual for the location of all grease fittings and recommended lubricants. This chart provides specific details regarding the type of grease required for each lubrication point. The tractor has several points that need to be lubricated.
Use a high-quality grease gun to apply grease to each fitting until fresh grease emerges, indicating that the old grease has been displaced. Wipe away any excess grease to prevent dirt and debris from accumulating. Be careful not to over-grease bearings and bushings, as this can damage seals and attract contaminants. Overgreasing is very common and needs to be avoided. It can cause components to fail prematurely.
Pay particular attention to lubrication points that are exposed to harsh conditions, such as those near the ground or in dusty environments. Lubricate these points more frequently to ensure adequate protection. Consider using a grease that is designed to withstand the high temperatures and heavy loads that are typical of tractor operation. Consider checking the points that need lubrication daily to make sure you have it done.
Maintaining the proper fluid levels is essential for the smooth and efficient operation of your John Deere 790. Low fluid levels can lead to overheating, component damage, and reduced performance. Regularly check the levels of engine oil, coolant, hydraulic fluid, and transmission fluid, as outlined in the maintenance schedule. Be sure to check the fluid with the tractor being turned off.
Use the dipsticks or sight glasses provided to accurately assess the fluid levels. Add fluid as needed to bring the levels within the recommended range. Always use the correct type of fluid specified in this manual to avoid compatibility issues and potential damage. The manual provides this information for all fluids. Always consult the manual before adding or replacing fluids.
Follow the recommended intervals for fluid replacements, as outlined in the maintenance schedule. Old or contaminated fluids can lose their lubricating properties and damage internal components. Properly dispose of used fluids according to local regulations. Changing the fluids is a very important step, as you don't want to ruin the engine or any other components. It is also good to document when the fluids are changed, so you know when the next replacement is due.
Filters play a crucial role in protecting the engine and hydraulic system from contaminants that can cause wear and damage. Regularly replacing the oil, fuel, and air filters is essential for maintaining optimal performance and extending the life of your John Deere 790. Dirty or clogged filters can restrict flow, reduce efficiency, and lead to serious problems. It is best to change all three filters when doing maintenance.
Refer to the maintenance schedule for the recommended filter replacement intervals. Always use genuine John Deere filters or equivalent replacements that meet the manufacturer's specifications. These filters are designed to provide the optimal filtration and protection for your tractor. The filters will protect your engine and hydraulic systems.
When replacing filters, be sure to follow the proper procedures outlined in this manual. This includes pre-lubricating the oil filter, priming the fuel filter, and properly seating the air filter. Improperly installed filters can leak or allow contaminants to enter the system, negating their protective function. Consider looking online for videos demonstrating the proper way to replace filters, this may help you understand better.
The battery is a vital component of your John Deere 790, providing the power needed to start the engine and operate electrical systems. Proper battery maintenance is essential for ensuring reliable performance and extending its lifespan. Regularly inspect the battery terminals for corrosion and clean them with a wire brush and baking soda solution. Corrosion can impede electrical flow and prevent the battery from charging properly.
Ensure that the battery is securely mounted and that the cables are tightly connected. Loose connections can cause voltage drops and prevent the engine from starting. Check the battery's electrolyte level and add distilled water as needed to keep the plates submerged. Avoid overfilling the battery, as this can cause acid to spill and damage surrounding components. Distilled water is very important as it doesn't contain any minerals that can damage the battery.
When storing the tractor for extended periods, disconnect the negative (-) battery cable to prevent parasitic drain. Consider using a battery maintainer to keep the battery charged and prevent sulfation. Sulfation occurs when the battery is left discharged for too long, reducing its capacity and lifespan. Keeping the battery maintained will extend its life.
Maintaining your John Deere 790 tractor in peak condition requires understanding and addressing common issues that may arise. Regular inspections are key to identifying potential problems early, preventing them from escalating into major repairs. Start by visually inspecting fluid levels, hoses, belts, and tires. Listen carefully for unusual noises during operation, and pay attention to any changes in performance, such as reduced power or difficulty starting. A proactive approach to maintenance significantly reduces the likelihood of unexpected breakdowns.
One of the most frequent issues tractor owners face is difficulty starting the engine, often caused by a weak battery, faulty starter motor, or clogged fuel filter. Check the battery voltage and connections first, ensuring they are clean and tight. If the starter motor is sluggish, it may need to be replaced or rebuilt. A clogged fuel filter restricts fuel flow, so replacing it regularly is crucial. Furthermore, always ensure the fuel system is properly primed, especially after changing the fuel filter or if the tractor has been sitting unused for an extended period. Remember to always disconnect the battery before any electrical work, and consult your local John Deere dealer for advice before dismantling any major components.
Engine problems can manifest in various ways, including loss of power, excessive smoke, overheating, or unusual noises. A loss of power might indicate issues with the fuel system, such as a malfunctioning fuel pump or injector. Black smoke usually suggests incomplete combustion, often caused by a rich fuel mixture or faulty injectors. Blue smoke typically indicates burning oil, which could be due to worn piston rings or valve seals. Overheating can be caused by a low coolant level, a faulty thermostat, or a clogged radiator. Regular servicing of your cooling system is essential.
When diagnosing engine noises, try to pinpoint the exact location and type of sound. A knocking noise might indicate a problem with the connecting rods or crankshaft bearings. A hissing sound could suggest a leak in the exhaust system or a vacuum leak. Ticking noises are often associated with valve train issues, such as worn rocker arms or loose valve clearances. Address these issues promptly to prevent further damage and costly repairs. Remember, always follow the recommended service intervals in your owner's manual and consult with a qualified mechanic when necessary.
The hydraulic system is critical for operating various tractor functions, including the loader, backhoe, and three-point hitch. Common problems include slow or erratic movement, loss of lifting capacity, or leaks. Start by checking the hydraulic fluid level and condition. Low fluid levels can cause cavitation and reduce performance. Contaminated fluid can damage hydraulic components, so regular fluid changes are essential. Inspect all hydraulic hoses and fittings for leaks, and replace any damaged or worn parts.
If you suspect a hydraulic pump issue, check its output pressure using a pressure gauge. A faulty pump may not generate enough pressure to operate the hydraulic system effectively. If the hydraulic cylinders are leaking or malfunctioning, they may need to be rebuilt or replaced. Furthermore, check the hydraulic control valves for proper operation, as they can sometimes become clogged or damaged, affecting the system's performance. Remember to relieve pressure in the hydraulic system before disconnecting any lines to avoid injury and equipment damage.
The electrical system powers many essential functions, including starting the engine, operating the lights, and controlling various tractor components. Common electrical problems include a dead battery, blown fuses, faulty wiring, or malfunctioning switches. Start by checking the battery voltage and connections, ensuring they are clean and tight. Use a multimeter to test fuses and wiring for continuity. Replace any blown fuses with the correct amperage rating.
If the tractor fails to start, check the starter solenoid and ignition switch. A faulty solenoid may prevent the starter motor from engaging. A malfunctioning ignition switch can interrupt the flow of electricity to the starter circuit. If the lights are not working, check the bulbs and wiring connections. Look for any signs of corrosion or damage. Remember to disconnect the battery before working on the electrical system to avoid electrical shocks and damage to components. Use a wiring diagram to trace circuits and identify potential problems.
The transmission is responsible for transferring power from the engine to the wheels. Common transmission problems include difficulty shifting gears, unusual noises, slipping gears, or loss of drive. Start by checking the transmission fluid level and condition. Low fluid levels can cause slippage and damage to transmission components. Contaminated fluid can reduce lubrication and accelerate wear. Inspect the shift linkage for proper adjustment, and ensure there is no binding or excessive play.
If you hear unusual noises coming from the transmission, try to identify the type of sound. Grinding noises may indicate worn gears or synchronizers. Whining noises could suggest a problem with the bearings. Slipping gears often indicate worn clutch plates or damaged gears. If you experience a loss of drive, check the axles and differential for damage. Transmission repairs can be complex, so it's often best to consult with a qualified mechanic for diagnosis and repair. Always use the recommended transmission fluid and follow the manufacturer's instructions when servicing the transmission.
Understanding the various parts and components of your John Deere 790 tractor is crucial for effective maintenance and repair. Familiarizing yourself with the location and function of each major part will significantly aid in troubleshooting issues and performing routine servicing. This includes knowing the difference between the engine components, such as the fuel injectors, water pump, and starter motor, as well as the hydraulic system parts, like the pump, control valves, and cylinders. The more comfortable you become with identifying these key components, the more efficiently you'll be able to diagnose problems and order the correct replacement parts. This knowledge empowers you to maintain your tractor proactively and potentially avoid costly repairs down the line.
Let's delve into the key areas of the tractor. The engine is the heart of the 790, providing the power for all its functions. Key engine parts include the fuel system (fuel tank, fuel lines, fuel filter, fuel pump, and injectors), the cooling system (radiator, water pump, thermostat, and fan), and the lubrication system (oil pump, oil filter, and oil pan). Then there's the transmission, which transfers power from the engine to the wheels. Understanding the clutch, gears, and differential is vital for smooth operation. Finally, there's the hydraulics system, which powers the loader, backhoe, and other implements. Key components include the hydraulic pump, control valves, cylinders, and hoses. Taking the time to visually locate and understand these systems on your tractor will prove invaluable.
The John Deere parts catalog is an indispensable resource for identifying and ordering replacement parts. It provides detailed exploded views and part numbers for every component of your 790 tractor. Using the catalog effectively requires understanding its organization and how to locate the specific parts you need. Start by identifying the section related to the area of the tractor you're working on, such as the engine, transmission, or hydraulics. Each section is further divided into subsections, allowing you to pinpoint the exact component you're looking for. Spend some time navigating the catalog to become familiar with its structure and learn how to efficiently find the information you need. This will save you time and frustration when ordering replacement parts.
Within the parts catalog, each component is typically illustrated in an exploded view, showing its individual parts and their relationship to one another. Each part is labeled with a unique part number. This number is crucial when ordering replacements, as it ensures you receive the correct item for your specific tractor model. Pay close attention to the notes and descriptions associated with each part, as they may contain important information about compatibility, superseded parts, or special installation instructions. Understanding these details will prevent errors and ensure that the replacement part functions correctly. The parts catalog is your roadmap to keeping your 790 running smoothly.
Once you've identified the correct part number using the parts catalog, you're ready to order replacement parts. John Deere parts can be ordered through authorized John Deere dealers or online retailers. When ordering from a dealer, be sure to provide the correct part number and any other relevant information, such as the tractor's serial number. This will help the dealer ensure that you receive the correct parts for your specific model. If ordering online, double-check the part number and description before submitting your order. Verify the retailer's return policy in case of any errors or discrepancies.
Before placing your order, consider the lead time for delivery and any shipping costs. If you need the part urgently, inquire about expedited shipping options. It's always a good idea to order a few extra common wear items, such as filters, belts, and hoses, to have on hand for future maintenance. Keep a record of your parts orders, including the part numbers, quantities, and dates of purchase. This information will be helpful for future reference and can assist you in tracking your maintenance history. Proper record-keeping and careful ordering are essential for maintaining your John Deere 790 effectively and keeping it in top operating condition.
The John Deere 790 tractor is designed with versatility in mind, capable of accepting a wide range of attachments and implements to tackle diverse tasks. Understanding which attachments are compatible is crucial for both performance and safety. Always consult your tractor's operator's manual and the attachment's documentation to ensure proper compatibility. These resources will provide vital information regarding weight limits, hydraulic requirements, and proper mounting procedures, helping you avoid potential damage to your tractor or the attachment itself. Remember, using incompatible attachments can lead to equipment failure, personal injury, and voiding of your warranty. Before purchasing any new attachment, double-check compatibility charts and consult with your local John Deere dealer for expert advice.
Beyond checking basic compatibility, consider the specific tasks you intend to perform with the attachment. Different implements require varying levels of horsepower, hydraulic flow, and PTO speed. A light-duty mower, for example, will demand less power than a heavy-duty rotary cutter or a large tiller. Overloading your tractor with an implement that exceeds its capabilities can lead to decreased performance, increased fuel consumption, and accelerated wear and tear on critical components. Properly matching your attachment to the tractor's capabilities ensures efficient operation and extends the lifespan of both your equipment and the implement itself. Prioritize understanding the specific requirements of each attachment before putting it into service.
Proper installation of attachments is paramount for safe and effective operation. Always begin by thoroughly reading the installation instructions provided with the attachment. These instructions will detail the correct mounting procedures, torque specifications for bolts, and any necessary adjustments. Before starting the installation process, ensure the tractor is on a level surface, the engine is turned off, and the parking brake is engaged. Disconnect the battery's negative terminal for added safety, preventing accidental starts or electrical shorts during the installation process. Taking these precautions minimizes the risk of injury and potential damage to your equipment.
After physically mounting the attachment, carefully connect any necessary hydraulic hoses or electrical connections, following the manufacturer's instructions precisely. Ensure all connections are secure and free from leaks before starting the tractor. If the attachment utilizes the tractor's PTO (Power Take-Off), verify that the PTO shaft is properly aligned and engaged. Never operate the PTO with misaligned or damaged shafts, as this can result in catastrophic failure and serious injury. Once all connections are verified, perform a thorough visual inspection of the attachment and its mounting hardware, double-checking for loose bolts, damaged parts, or any other potential hazards. Only after completing these steps should you proceed with testing the attachment.
When operating an attachment for the first time, start slowly and cautiously, gradually increasing the speed and workload as you become more familiar with its operation. Be mindful of the attachment's limitations and avoid exceeding its recommended operating parameters. Regularly monitor the attachment for any signs of malfunction, such as unusual noises, vibrations, or overheating. If you observe any problems, immediately stop the tractor and investigate the issue. Promptly addressing minor issues can prevent them from escalating into more significant and costly repairs. Consistent vigilance and attention to detail are key to ensuring safe and productive operation with any tractor attachment.
Operating tractor attachments involves inherent risks, and prioritizing safety is crucial to prevent accidents and injuries. Always wear appropriate personal protective equipment (PPE), including safety glasses, hearing protection, gloves, and sturdy footwear, when working with attachments. Be aware of your surroundings and maintain a safe distance from bystanders, especially children and animals. Before engaging any attachment, clear the work area of any obstructions, such as rocks, branches, or debris, that could be thrown or damaged by the implement. Familiarize yourself with the attachment's safety features, such as guards, shields, and warning labels, and ensure they are properly installed and functional.
Never attempt to adjust, repair, or service an attachment while the tractor is running or the PTO is engaged. Always disengage the PTO, turn off the engine, and set the parking brake before performing any maintenance or adjustments. When transporting attachments on public roads, ensure they are properly secured and comply with all local traffic regulations. Use appropriate lighting and reflectors to enhance visibility, especially during low-light conditions. Remember, defensive driving practices and adherence to traffic laws are essential for safe transportation of tractor attachments.
Regularly inspect your attachments for wear and tear, paying particular attention to blades, tines, bearings, and hydraulic hoses. Replace worn or damaged parts promptly to prevent equipment failure and potential accidents. Store attachments in a safe and secure location when not in use, preventing unauthorized access and minimizing the risk of damage from weather or other factors. Educating yourself and others about the safe operation of tractor attachments is a continuous process. Consistently reinforce safe practices and promote a culture of safety on your farm or property. Prioritizing safety at all times is the best way to ensure a positive and accident-free experience with your John Deere 790 and its attachments.
Preparing your John Deere 790 for an extended period of storage is crucial for ensuring its longevity and optimal performance when you're ready to put it back into service. Failing to properly prepare your tractor can lead to a multitude of issues, including corrosion, battery degradation, fuel system problems, and even damage to vital engine components. A meticulous approach to preparation will save you time, money, and frustration in the long run. This involves more than just parking it in a shed; it requires a series of steps designed to protect each system of your tractor from the detrimental effects of inactivity and environmental factors. By dedicating the time to properly prepare your John Deere 790 for storage, you're investing in its future reliability and performance.
Begin by thoroughly cleaning the tractor, removing all dirt, mud, and debris. Use a pressure washer or garden hose with a nozzle to blast away any accumulated grime. Pay special attention to the engine compartment, undercarriage, and around the wheels, as these areas tend to collect the most dirt. Once the tractor is clean, allow it to dry completely before proceeding. Next, lubricate all grease fittings according to the maintenance schedule outlined in the owner's manual. Fresh grease will protect moving parts from corrosion and ensure smooth operation when the tractor is restarted. Don't forget to check and top off all fluid levels, including engine oil, coolant, hydraulic fluid, and transmission fluid. Low fluid levels can contribute to internal corrosion and damage during storage.
Fuel stability is a major concern during long-term storage. Untreated gasoline can degrade and form gummy deposits that clog fuel lines and carburetors, leading to starting problems and poor engine performance. To prevent this, add a fuel stabilizer to the fuel tank according to the manufacturer's instructions. Run the engine for a few minutes after adding the stabilizer to ensure it circulates throughout the fuel system. If possible, it's best to fill the fuel tank completely to minimize condensation and prevent rust formation inside the tank. Consider draining the carburetor if you are not using fuel stabilizer. For diesel engines, make sure to add a diesel fuel stabilizer. This ensures optimal fuel system health and reliability when your tractor comes out of storage.
The location where you store your John Deere 790 plays a significant role in its overall preservation. An ideal storage location should be dry, well-ventilated, and protected from the elements. Storing your tractor outdoors without adequate protection exposes it to rain, snow, sun, and fluctuating temperatures, all of which can accelerate corrosion and deterioration. Indoor storage is always preferred, but if that's not an option, a heavy-duty waterproof cover is essential. Ensure the cover is breathable to prevent moisture buildup underneath, which can lead to rust. A tightly sealed, non-breathable cover can trap condensation and create a humid environment, doing more harm than good.
When selecting a storage location, consider the risk of rodent infestation. Mice, rats, and other rodents can wreak havoc on your tractor by chewing on wires, hoses, and upholstery. They may even build nests inside the engine compartment or air cleaner. To deter rodents, clear away any vegetation or debris around the storage area. Place rodent traps or baits nearby, and consider using rodent repellent sprays around the tractor. Regularly inspect the storage area for signs of rodent activity and take corrective action if necessary. Preventing rodent damage is a key aspect of protecting your investment and ensuring your tractor is ready to go when you need it.
If you are storing your tractor on a concrete floor, place wooden blocks or planks under the tires to prevent them from coming into direct contact with the concrete. Concrete can draw moisture from the tires, leading to premature cracking and deterioration. Slightly overinflating the tires before storage can also help prevent flat spots from developing. Consider removing the battery and storing it in a cool, dry place, preferably on a trickle charger to maintain its charge. This prevents the battery from discharging completely, which can damage its cells and shorten its lifespan. Store the battery in a safe location away from flammable materials.
After a period of storage, it's essential to perform a thorough inspection and maintenance check before starting your John Deere 790. Rushing this process can lead to serious mechanical problems. Start by visually inspecting the tractor for any signs of damage, such as leaks, cracks, or corrosion. Check all fluid levels and top off as needed. Inspect the tires for proper inflation and any signs of cracking or deterioration. Ensure the battery is fully charged and properly connected. Before attempting to start the engine, check the air cleaner for obstructions and clean or replace it as necessary. A clogged air cleaner can restrict airflow and affect engine performance.
Once you've completed the visual inspection, it's time to start the engine. Before cranking, turn the engine over manually by hand using a wrench on the crankshaft pulley. This will help distribute oil throughout the engine and prevent dry starts. Start the engine and let it idle for a few minutes to allow it to warm up. Listen for any unusual noises or vibrations. Check the gauges to ensure everything is functioning properly. If the engine is running rough or emitting excessive smoke, shut it down and investigate the cause. A rough running engine could be a sign of contaminated fuel. This is more common when stabilizer wasn't used or not used properly.
Finally, before putting your John Deere 790 back into service, perform a test run to ensure all systems are functioning correctly. Check the brakes, steering, and hydraulic functions. Operate all attachments to ensure they are working properly. If you encounter any problems, address them promptly before using the tractor for any heavy work. Taking the time to perform a thorough post-storage inspection and maintenance check will help ensure your John Deere 790 is ready to tackle any task you throw its way, safely and reliably. Remember to consult your owner's manual for specific maintenance recommendations and schedules.
The heart of the John Deere 790 is its reliable and robust Yanmar 3TN75RJ liquid-cooled, 3-cylinder diesel engine. This engine is known for its efficiency and durability, providing ample power for a variety of tasks. It delivers a gross power output of approximately 30 horsepower (22.4 kW), ensuring sufficient performance for tilling, mowing, and loader work. The engine operates at a rated speed of around 2800 RPM, maximizing its efficiency and lifespan. Regular maintenance, including oil changes and filter replacements, is crucial for maintaining the engine's optimal performance and extending its service life.
The Yanmar 3TN75RJ engine is designed with a direct injection system, which contributes to its fuel efficiency and cleaner emissions. This system precisely delivers fuel into the combustion chamber, optimizing the combustion process and reducing wasted fuel. The engine also features a full-pressure lubrication system, ensuring that all moving parts are properly lubricated to minimize wear and tear. Proper cooling is essential for diesel engines, and the liquid cooling system in the 790 is highly effective at maintaining the engine's optimal operating temperature, even under heavy loads. Understanding these key engine features can help operators properly maintain and troubleshoot any potential issues.
The John Deere 790 boasts a capable hydraulic system that powers its various implements and attachments. The open-center hydraulic system provides a reliable flow of hydraulic fluid to the tractor's loader, backhoe, and other hydraulic-powered accessories. It offers a hydraulic pump flow of approximately 5.7 gallons per minute (21.6 liters per minute), providing adequate power for most tasks. The hydraulic system operates at a working pressure of approximately 2,275 PSI (157 bar), allowing for effective operation of hydraulic cylinders and motors.
The hydraulic system includes features such as a three-point hitch with a lift capacity of approximately 1,600 lbs (726 kg) at the pivot points, making it suitable for handling a variety of implements. Regular maintenance of the hydraulic system is crucial for preventing leaks and ensuring optimal performance. This includes checking the hydraulic fluid level, inspecting hoses and fittings for damage, and replacing the hydraulic filter according to the manufacturer's recommendations. Proper operation of the hydraulic system involves understanding the function of the control levers and adjusting the flow rate as needed for different tasks.
The John Deere 790 is equipped with a reliable mechanical transmission that provides a range of speeds for different operating conditions. It typically features a 9-forward and 3-reverse gear transmission, allowing for precise speed selection for various tasks. This range of gears allows the operator to select the optimal speed for tilling, mowing, or hauling, maximizing efficiency and productivity. The transmission is designed for smooth and reliable operation, providing consistent performance under varying loads.
The transmission also features a synchronized shuttle shift, which allows for smooth transitions between forward and reverse gears without the need to fully stop the tractor. This feature is particularly useful for loader work and other tasks that require frequent changes in direction. Regular maintenance of the transmission is essential for ensuring its longevity and performance. This includes checking the transmission fluid level, inspecting the shift linkages, and replacing the transmission filter according to the maintenance schedule. Understanding the operation of the transmission and performing regular maintenance will help prevent costly repairs and downtime.
Understanding the dimensions and weight of the John Deere 790 is crucial for transportation, storage, and operating in confined spaces. The overall length of the tractor is approximately 115 inches (292 cm), while its width is around 54 inches (137 cm). The height to the top of the ROPS (Roll Over Protection Structure) is approximately 90 inches (229 cm), providing essential safety protection for the operator. The operating weight of the tractor is approximately 2,600 lbs (1,179 kg), depending on the specific configuration and attachments.
The wheelbase of the tractor is approximately 63 inches (160 cm), contributing to its stability and maneuverability. The ground clearance is approximately 13 inches (33 cm), allowing the tractor to navigate uneven terrain without damaging the undercarriage. Understanding these dimensions and weight specifications can help operators make informed decisions about implement selection, transportation requirements, and operating in various environments. When transporting the tractor, it's essential to use appropriate tie-down straps and follow all safety guidelines to ensure secure transport.