7 Most Common Kubota L3901 Problems

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By Marvin Tucker

Farming Equipment

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The new L-series from Kubota takes the already great foundation that the original 3901 had and builds on it with a bold new look and a slew of technical upgrades over the original, including everything from improved performance to visibility and comfort.

Not only that, Kubota is a well-trusted brand, and this model has received overwhelmingly positive user reviews. Sounds perfect, right?

Unfortunately, the Kubota tractor suffers from some common issues that, if you are a prospective buyer, you should be aware of.

So in this article, we will cover all the common problems an l3901 tractor owner will encounter and how to fix them. As well as share our thoughts on whether the l3901 is a worthy investment of your hard-earned cash.

The most common problems with the Kubota L3901

As we mentioned, Kubota is a well-respected brand. Many problems and issues you will encounter with one of their tractors are not necessarily due to some flaw with the machine but common issues you’ll face with any good tractor.

The key to having a machine that will stand the test of time is to keep a consistent and robust maintenance routine to stay on top of the engine, hydraulic, and electronic problems that can crop up.

1. The engine does not crank

If you’ve owned a tractor in the past, this is undoubtedly something you would have run into already. Sometimes the engine will suddenly not be able to crank or take an exceptionally long time.

The most common cause of this problem is the battery, or perhaps the battery is functionally ok. Still, the connections/cables have eroded, become damaged, or have excessive dirt, and debris has made its way into the housing and is interfering with something.

Fortunately, diagnosing and fixing the issue is quite simple. The first thing to do is ensure the battery is charged and that all the connections are tight and secure, as they may have worked themselves loose over time.

The next thing to check is that the area is clean. Look for excessive dirt and corrosion that may be present on the connections, which may be cleaned with a steel wire brush.

If you have inspected everything thoroughly but noticed that the battery is running out of charge very quickly, it may be a defective case. Then you may need to replace it. If you are confident in doing so, you can do this yourself. Otherwise, contact a local dealer/repairer to do the job.

2. The engine is overheating

A widespread issue that users have reported on the l3901. There are a few potential causes that might trigger the engine to overheat.

It could be a result of the radiator being clogged with dirt, limiting the airflow that can pass through the machine, thus removing its ability to push the hot air out and resulting in the engine becoming progressively hotter.

In this scenario, you need to clean out the radiator fins. Something like compressed air is also convenient here.

In addition, you may also want to check the engine’s cooling fluid to ensure it’s adequately topped up, as too little will cause the engine to heat up.

 If the cooling fluid is already quite old, particularly if you notice any debris floating there, the best thing is to flush the system and re-fill it with new cooling fluid.

3. Regeneration problems

While not available on every tractor, regeneration automatically cleans the DPF (Diesel Particulate Filter) when certain conditions are met. This can present a safer and healthier work environment, mainly if you use the tractor for long periods.

Sometimes this process can be activated manually, or you can perform a parked regen that requires you to stop working and part the tractor.

Of course, this is a wonderful feat of technology, but some users have reported that the regen LED should switch off when the regeneration process starts. Instead, it continues to flash, which can be very perplexing if you don’t know what’s happening.

One quick fix you can perform to prevent the light flash is to speed up the engine to where it’s now outside of the required regeneration criteria, and this will often turn the indicator off.

Be sure to leave the tractor for at least 15 minutes to ensure the regeneration process can finish.

If these solutions do not work, you should contact a repairer as there may be an issue with the filter you want to address for your long-term health.

4. The engine turns itself off for no reason

This is another prevalent issue users have reported experiencing, and although it may seem quite catastrophic, don’t panic! It’s usually a fixable issue relating to the fuel line, pump, or air filter.

The first thing to check is that there is adequate fuel in the tractor, as fuel starvation is the most common cause of this problem

The next thing to check is the fuel pumps and lines. Check for any clogged lines or damaged components and replace them as necessary. You can clean the fuel lines yourself, but if the fuel pump needs replacing, it’s best to contact a mechanic.

The final thing to check is the air filters. For an engine to run efficiently, it needs to have the correct air-to-fuel ratio, so even when the pump lines are working, if the air filter is clogged, it won’t be able to supply enough air to the engine, potentially causing it to shut off.

5. Power Take-off failure

Power Take-off (otherwise known as PTO) is responsible for transferring an engine’s power to another piece of equipment. Particularly important in something like a tractor where there will be additional equipment attached to the engine.

But of course, it can be very troublesome if this doesn’t work, and some users have reported that the primary power take-off shart either does not turn when it should be engaged or will turn by itself when it’s not correctly engaged.

Here are the things you need to check to restore the PTO to working order:

  • Check that the PTO is correctly connected to the power supply and that the power supply is providing power to the PTO
  • The next thing to check is the clutch pack and ensure it’s all in good working order and repaired as needed
  • Next, you should check the PRO control valve by performing a pressure test to ensure the seal is good. If it turns out to not be good, it will need replacing.

6. Difficulties with the steering

Sometimes users might experience excessive resistance when trying to steer their tractor. Or conversely, they might find that the steering is too loose and not responsive enough. They may also find that it pulls over to one side during operation.

This can be a reasonably broad issue to occur with several potential causes.

Generally speaking, on the l3901 tractor, a steering issue is caused by air making its way into the hydraulic system, or possibly the cylinders are experiencing a problem.

Check there is sufficient hydraulic fluid in the machine, and you may also need to potentially bleed it to ensure any air in the system can be removed.

You should also check the fuel/oil levels, as they can contribute to this issue.

Next, you should check if there is equal pressure between all the tires. If one has less pressure than the others, it will cause the chassis to dip and pull over to that side.

The final thing to check is the battery. Ensure all the connections to the battery are secure, and check each connection for corrosion or wear. You will need to replace any faulty components and possibly brush the connection points with a steel wire to remove said corrosion or debris.

7. Electrical issues

This is quite a broad issue that may affect many aspects of the tractor.

If you find that the tractor doesn’t start, it may be due to an issue with the spark plug. This is responsible for generating a small electrical current that ignites the fuel and creates the combustion process.

If the spark plug gets clogged by any debris, it can interfere with its ability to generate a spark then the tractor will not start.

Fortunately, these are cheap and simple to replace and can be done by yourself without the assistance of a Kubota dealer. You need to wiggle both ends of the sparkplug free and reinstall a new one.

You may also see corrosion or debris in the sparkplug and be tempted to try and clean it. It’s just not worth it as they are such cheap components. Just use a new one to ensure your Kubota tractor operates at maximum efficiency.

Kubota L3901 problems: Are they a deal-breaker?

The Kubota l3901 is an excellent tractor. Many users have been using it for years, and while it suffers from some issues, these issues are not unique to the l3901 and can, by and large, be circumvented with a reasonable care and maintenance routine.

For this reason, we have no reservations about recommending the Kubota l3901. It’s a reliable, powerful, and versatile machine praised for its user accessibility and features. A worthy investment of your hard-earned money!

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