9 John Deere 790 Problems and Solutions

As with every machinery with downsides, the John Deere 790 is no exception. It is a compact utility tractor operating on a three-cylinder diesel engine.

As a smaller tractor, it works for all kinds of farming activities and other tasks, like using it to push snow slightly forward around the house or brush hogging.

However, users have complained about facing specific issues while using it over the years. Have you used one before, or do you own one?

Well, this article talks about some John Deere 790 problems as well as solutions to these problems.

Read: Troubleshooting John Deere Gator 835M Problems

John Deere 790 Problems

Some problems could come up with using this tractor, but the good news is that there are also quick fixes.

Now let us talk about nine issues that you might be faced with if you decide to make use of a 790.

1. The Unit is not Starting

One of the common problems with this tractor is that it might not kickstart at the first turn of its ignition key; that is, the engine might not start.

This is one discussion starter about this tractor, especially when the engine shuts down.

This could happen for a lot of reasons. Here are some of them

For one, the transmission gearshift lever could be in the wrong position instead of neutral. It usually comes with manual steering for the 2WD model while hydrostatic power steering for the 4WD kind.
So if you are not used to driving either, you might shift the gear drive in the wrong direction resulting in low tire pressure.
This could also result from the John Deere 790’s throttle lever not being pushed forward.
It is also essential to check the fuel as there could be inadequate or stale fuel that needs to be drained.
The engine oil could also have the wrong viscosity, leading to the fuse being blown.
Leaving it out in the cold too long could result in the cylinder not combusting, thereby refusing to start.
Parts connected could also be corroding or even fall out of place.
Both fuel and air filters could be plugged by debris making them dirty. They could also be damaged.

2. Electrical Issues

There could also be some issues with the electrical parts of a John Deere 790. The good side is that they are primarily minor faults but could affect the proper functioning of the tractor if not rectified.

A switch or electrical part could be due for a change. However, you can prevent this if the tractor is taken for monthly servicing.

These regular checks will ensure any error with the electrical parts is corrected and parts that need replacement are fixed.

It will also save you from any future faults later which could happen unexpectedly, such as the engine knocking.

3. Faulty Front-end Loader

The front loader, also known as the wheel loader, is the part of the tractor operated to pick, excavate, load, and move materials. This is also the part most users have issues with.

The tractor’s loader requires certain adjustments to function properly because it has an under-engineered front-end drive on the wheels.

So if this front-end loader is not properly fixed or installed, it might not work well. To get it to proper functioning, you need to do the following, especially if you are reattaching a new one:

Remove the dust caps and check the lines for dirt residue trapped before reconnecting the hydraulic lines.
Use a loader joystick to pull it forward into the implement.
Bring the knuckles lower on both sides to put them in place.
Lift the bucket slowly into place.

This faulty front-end loader problem is common with other John Deere tractors, such as the 4066r tractor and John Deere 790 models.

4. Inadequate Fuel Flow

This is another problem with this tractor. Several parts should be checked if adequate fuel is not flowing to power your tractor.

It could be a result of one of them being faulty or in need of replacement. You want to check the fuel tank, electric fuel pump, fuel filter, and injector.

Low oil viscosity could also result in the fuel being burned faster than it should; hence you want to also check for this.

This is one of the leading causes of engine overheating, a bigger problem.

5. Drive-belt Issues

A faulty drive belt could result in the tractor not moving forward or smelling like it was heating up. In this case, the belt needs replacement.

It is advised to follow a guide or manual to do this so as not to tamper with other parts around the drive belt.

The spark plug wire, deck, and battery are usually disconnected for the old ground drive belt to be removed before a new one is put in as a replacement.

See: John Deere ztrak 757 problems

6. Stalling Unexpectedly

The John Deere could also begin to stall at any moment for no reason. This is one of the most common problems of the unit not starting.

The common cause for this is usually a result of clogged valves or faulty john deere 790 fuel filters.

These valves and filters could require thorough cleaning or maintenance, so the tractor system is slow.

You want to do an in-depth check of the entire fuel system so this does not result in further problems.

7. Leaks in Fittings

After use over some time, the fittings of the 790 are prone to leaks. It could cause a delay in your work as these fittings take a minute to get fixed.

This is why general maintenance is advised as often as possible, mainly when your tractor has been used for years.

If inspection is done when it should be, those leaks will be fixed and even prevented before they cause further problems.

8. Underperformance

If the tractor system begins to underperform, it is a cause for alarm. Underperformance happens when John Deere finds it very difficult to do the work it used to do effortlessly before.

Insufficient hydraulic fluid is the likely cause of this problem. If it is not topped up or replaced when it should be, it could go below the level for the tractor’s proper operation.

So checking the hydraulic fluid reservoir should be done as often as possible if you want the John Deere to work at its optimum.

This could also happen when it is due for servicing, or the system is generally aging.

9. Disrupted Flow of Oil to the Engine

If the engine does not get an adequate flow of oil, it could affect the proper functioning of the tractor. This means the engine would not start, and your John Deere would not move.

This could happen for several reasons, some of which are:

The strainer getting plugged up from debris constantly sucking into the filter whenever the engine is shut down and restarted.
There could be a small hole in the fuel line that lets air in.
The injector pump and lift pump could have debris stuck in them, so they need to be checked. Worse still, it could be faulty.

All the above problems could be rectified with simple clean-ups and checks, but when specific tools are used in testing, you might need to take them to where you bought the tractor.

How to Fix John Deere 790 Problems

There are several solutions to the problems described above. They are also specific fixes to the issues with the 790.

Overall, good upkeep habits, regular maintenance, and servicing of parts of the tractor would go a long way in preventing some of these problems.

Some of these solutions are:

You want to ensure all connections within the tractor’s hydraulic lines are clean and tight. This can be done using a wire brush.
Ensure you drain stale fuel, replacing it with new fuel filled to the required level.
Check and measure the fuse from time to time to make sure it is not blown. If it is, you should replace the blown fuse.
Always check to see if the fuel is getting to the cylinder, as the lines could be clogged preventing proper flow.
The engine’s temperature should be kept as high as possible so the cylinder can burn enough air and fuel it requires for functioning.
Regularly check the fuel tank, the filters, the electric fuel pump, the brush hog, the battery box, and the injector, as a fault in any of these parts could affect the functioning.
The oil viscosity should also be checked and replaced when necessary, as the wrong flow could affect the engine.
Also, as an added tip, be careful not to use this tractor for heavy tasks as they could strain the machine resulting in more problems.

Should You Use a John Deere 790?

With all these mentioned earlier, is this tractor a good buy? John Deere is known for making excellent tractors.

Most people go for the 790 because they need a compact tractor on a budget to do the work in their small space.

Also, it is reportedly very economical on diesel, and without all the problems described above, it runs smoothly.

So, you can go for this tractor if it meets the requirements you want. After all, it is a super little machine.

Read more on John Deere 1025r problems and fixes to learn more.

John Deere 790 Pros and cons

Pros:

Power Galore: The John Deere 790 is a beast with its 30 horsepower engine, ready to tackle any task like a champ!
Versatility on Steroids: Whether you need to mow, till, haul, or landscape, this tractor can do it all. It’s like having a Swiss Army knife on wheels!
Built Tough, Just Like a Viking: The 790 is as sturdy as a Viking ship, built to withstand the test of time and handle both residential and light commercial use without breaking a sweat.
Navigates Tight Spots Like a Ninja: With its compact size, this tractor can maneuver through narrow spaces with the agility of a ninja. Say goodbye to getting stuck between a rock and a hard place!
Comfort Fit for a King: The ergonomic design 790 ensures you can work like a boss without sacrificing comfort. Sit back, relax, and conquer your tasks with ease.

Cons:

Hulk May Want More: While the 30 horsepower is no joke, some users with Hulk-sized tasks might crave even more power.
Size Matters: The compact design that makes it nimble also means there are limits to the size of attachments it can handle. No attaching an aircraft carrier, folks.
A Bit of a Splurge: The John Deere 790 has a higher price tag than some competitors. Hey, quality comes at a price, right?
Noisy Neighbor: Brace your eardrums because this tractor can make some noise. It’s like having a mini-concert in your backyard.
Treasure Hunt for Parts: Finding specific parts for the 790 can sometimes be like searching for buried treasure. X marks the spot, but it may take a bit of digging to find what you need.

Troubleshooting John Deere 790 Problems

Problem	Causes	Solution
Unit not starting	– Transmission gearshift lever not in neutral	– Ensure transmission gearshift lever is in the correct position
	– Throttle lever not pushed forward	– Push the throttle lever forward
	– Inadequate or stale fuel	– Check and drain fuel if necessary
	– Wrong viscosity engine oil	– Check and replace engine oil if needed
	– Cylinder not combusting due to cold exposure	– Allow the engine to warm up before starting
	– Corroded or misplaced parts	– Inspect and replace any corroded or misplaced parts
	– Plugged or damaged fuel and air filters	– Clean or replace the fuel and air filters
Electrical issues	– Worn-out switch or electrical parts	– Regular monthly servicing to check and replace any worn-out electrical parts
Faulty front-end loader	– Improper installation or attachment of the loader	– Clean hydraulic lines before reattaching, ensure proper connection of lines and bucket and follow installation guidelines
Inadequate fuel flow	– Faulty fuel tank, electric fuel pump, fuel filter, or injector	– Check and replace faulty components, ensure proper fuel viscosity
Drive-belt issues	– Faulty drive belt	– Replace the drive belt following the guide or manual instructions
Stalling unexpectedly	– Clogged valves or dirty fuel filters	– Clean valves and fuel filters thoroughly
Leaks in fittings	– Wear and tear over time	– Regular maintenance and inspections to fix and prevent leaks
Underperformance	– Insufficient hydraulic fluid	– Check and top up or replace hydraulic fluid as needed
Disrupted oil flow	– Clogged strainer, air leak in the fuel line, or faulty injector and lift pump	– Clean or replace clogged components, repair or replace any faulty parts

FAQs

What are the pros of John Deere 790?

John Deere 790 is a compact utility tractor that efficiently works. It is fuel economy with a hydraulic system that ensures regular oil flow to all its parts.

Compared with other tractors, it does not make much sound, making it preferred for small residential areas.

What are the cons of John Deere 790?

John Deere 790 has several disadvantages. It is weak compared to other tractors, which makes it not as durable. It could also have starting issues when used initially.

The terminal connectors of its battery are inferior, which could lead to the parts disconnecting quickly. Regular maintenance and servicing must be done to keep it working optimally.

What category is a John Deere 790?

The John Deere 790 model belongs to the category one three-point hitch with a power take-off of 24 horsepower.

It has a three-cylinder diesel engine producing 30 horsepower. It could also come in 2WD or 4WD, where it comes in either manual or power steering.

Final Thoughts on John Deere 790 Problems

So now you know the problems typical with this tractor; you are not in the dark before you purchase or use one.

These problems could range from starting issues to inadequate oil flow, faulty electrical systems, leaking fittings, and unexpected stalling.

Some parts also need to be checked and regularly maintained, such as the drive belt, air, fuel filters, front-end loader, and cylinder.

All you have to do is carry out general servicing and regular checks so you can address any of these problems on time.

The John Deere 790 is a good tractor; when put to good use, you will get your money’s worth.