How to Troubleshoot John Deere 4040 Problems?

Owners expect long, trouble-free service from their John Deere tractors. And 90% of the time, they won’t encounter that many unexpected problems.

Despite providing excellent all-around performance, it occasionally suffers from engine or steering issues. 

So, what are the potential John Deere 4040 problems?

Like most tractors, the John Deere 4040  depends on several mechanical and electrical parts. If any of these fail, you may experience hydraulic, electrical, or other issues. Worn-out fuel system components cause the majority of these issues. However, there are other culprits as well.

But to address these problems, you must first identify them. This guide includes all potential problems and regular maintenance tips.

John Deere 4040 Engine Problems

Problem Reason Solution
Engine Hard Starting due to John Deere 4040 Engine Problems Closed shut-off valve.

Faulty injector.

Damaged injection pump, etc.

Open shut off valve.

Replace injector.

Rebuild or replace the pump, etc.

Engine Stops Unexpectedly Engine not warmed.

Improper Fuel injection.

Clogged Fuel filter, etc.

Fuel injection settings required.

Replace the filter element, etc.

Engine Starts and Immediately Stops Dirty fuel filter and air cleaner.

Faulty injection pump, etc.

Change or service air cleaner and fuel filter, etc.
Engine Stops when Idling Incorrect Idle speed setting.

Defective fuel injection pump. 

Dirty Fuel injector nozzle.

Adjust speed settings.

Repair the pump.

Service the nozzle, etc.

Engine Overheating Insufficient engine coolant.

Worn-out cooling parts.

Low Engine oil level.

Thermostat malfunctioning. 

Fill up the coolant and check the Cooling System.

Refill the oil tank of the engine.

Install new thermostat.

Loss of Engine Power Faulty fuel injectors  & Incorrect pressure of fuel injection.

Clogged Air filter element.

Plugged engine oil filter. 

Change fuel injectors.

Recheck the fuel pressure settings.

Service or replace the air filter.

Replace engine oil filter.

Engine Using too much Oil Worn-out gaskets or seals.

Incorrect Oil viscosity.

Damaged piston rings.

Broken pistons or cylinder liners. 

Defective parts should be replaced.

Use oil with correct viscosity.

Install new Piston ring.

Check and replace accordingly to solve the John Deere 4040 Engine Problems.

Most of the engine problems are related to the fuel system. But other parts or components can go wrong from time to time and create various engine problems. 

Problem 1: Engine Doesn’t Start

One of the worst engine problems to have is when your engine doesn’t start at all. It is usually a problem because of the fuel system. But a couple of other things can be behind it as well. 


Dirty fuel shut-off valves, filters, or injectors can easily prevent the engine from starting. The shut-off valve may occasionally be closed, preventing the engine from starting.

A damaged fuel injection pump can cause low compression, which makes it impossible to start the engine. Air can frequently get trapped in the fuel system, which makes it impossible to start the engine.


It is best to check each case separately to determine which is harming your engine. Simply remove the fuel filter and replace it with a new one.

Remove the shut-off valve from the compartment if it is closed, and see if something is causing it to keep closed. If not, put it back in and keep it open.

Getting a new injection pump and replacing the broken one is better. This will solve the low compression issue.

However, you should also inspect the cylinder block and replace any problematic parts to stop air from getting into the system.

Problem 2: Engine Stops Unexpectedly

Sometimes, the reason behind the engine stopping unexpectedly is not something major. Let’s check what could possibly be behind this problem.


Engine can stop unexpectedly for something as small as the engine not being warmed up. But the fuel system can be behind it as well.

It can be filled with dirt, water, or even air. Sometimes faulty fuel injectors can cause this as well. And the improper placement of fuel injection can stop the engine as well.


If the engine is not warm enough for it to run smoothly, you can turn on the engine and let it run for a couple of seconds before driving it.

But before warming up the engine, make sure to park it at a safe place. Drive the truck around the area slowly for the first 10 minutes then drive at your normal speed.

For the problem with the fuel system, check the injectors and fuel filters. If dirt or debris is stuck in the fuel system, remove the injector and clean it thoroughly. But buy a new fuel filter if there are broken or damaged parts.

Problem 3: Engine Stops During Idling

It’s better to keep your engine idle. This allows the engine to generate enough power to run smoothly and keep operating the power steering or the alternator.

But sometimes, while idling, the engine stops abruptly.


The engine unexpectedly shutting off while idling might be caused by four different things. However, two of them are related to fuel. Fuel injection pumps that are broken or defective make it difficult to idle.

As time goes on, the fuel injector nozzles clog, and the engine cannot receive enough fuel for idling.

The engine will occasionally shut off because the low idle speed settings are off, though. Incorrectly adjusted valve clearance can also cause the engine to shut down completely.


You can easily adjust the idle speed from the carburetor. You must adjust the screw on the primary throttle linkage on the driver’s side. 

You can easily adjust the valve clearance by tightening the screws. Usually, it gets moved by inches, and adjusting it back in place solves the issue. But it’s better to consult with a technician and get it fixed.

If the fuel injector nozzle is dirty, take it out, clean it, and put it back in its place. But if it’s damaged, buy a new one. It is better to replace the worn-out fuel injector pump too.

Problem 4: Engine Overheating

An overheated engine is one of the most significant issues any vehicle could experience. Overheating an engine can cause warping and cracking, leading to permanent damage.


Usually, the lack of engine coolant leads to the engine overheating. But the parts of the cooling system get damaged or clogged over time and cause the engine to overheat as well. 

If the engine oil level is too low and the fan belt tension is incorrect, a defective belt may be at fault.


First, you need to check the cooling system parts to see if any are damaged. If the belt tension seems too loose, adjust it, or change the belt. If any other parts are damaged, replace them with new ones.

For low-engine coolant, you can top it up with some more but ensure that there’s no crack in the cooling system that might drain the coolant in the first place.

Problem 5: Loss of Engine Power

Along with the engine failing to start or overheating, it can sometimes lose power completely. There are usually four main reasons behind it.


Faulty fuel injectors and incorrect fuel injection pressure are the main culprits behind this problem. Along with these, the air filter is clogged with dirt, and debris can easily lead to this issue. 

Even the engine oil filter gets clogged due to heavy use on the field.


To get the engine started again, you need to check all of these compartments carefully. One or two might be at fault, so it’s better to check thoroughly. 

First, check the fuel injectors and both filters. See if anything is damaged or not. If so, replace them with new ones.

For clogged filters, replace them with new ones. You can adjust the fuel pressure setting according to the recommended number from the manual or any automobile expert.

Problem 6: Engine Using Too Much Oil

Even if the tank was recently filled, tractors can use all the fuel. This typically happens when a significant oil leak or other system component is damaged.

It’s troubling because it can cause various other issues and be costly.


Engine using too much oil is a sign that the gaskets or the seals are damaged or completely broken. But sometimes, the oil viscosity isn’t correct, and the engine uses too much of it. 

At the same time, the piston ring can be broken, and even the cylinder liners can lead to too much oil use. 


Defective parts like gaskets or seals should be replaced after a primary inspection. You can find piston rings online and in hardware stores, along with cylinder liners. 

But for correct oil viscosity, you should definitely consult with an expert and replace the oil accordingly.

John Deere 4040 Electrical System Problems

Problem Reason Solution
Battery Does Not Charge due to John Deere 4040 Electrical System Problems Battery worn out.

Damaged Wire harness & connection cable.

Install new battery.

Change wire harness and connection cable. 

Slow or No Crank of Starter Motor  Defective Starter Motor.

Worn-out battery, wire harness.

Replace the Starter motor.

Recharge the battery, and replace the wire harness to solve John Deere 4040 Electrical System Problems.

In case of any vehicle’s electrical problem, it is usually the battery at fault. But sometimes the starter motor can be behind it as well.

Problem 1:  Battery Does Not Charge

For any tractor to function properly the battery of a tractor is the most important part. It needs to be well charged to get the electrical system working properly.

But oftentimes, your battery will face many issues that prevent it from charging properly.


Battery being worn out or in use for a long time simply can’t charge properly. The electrical wires connecting the battery to the tractor can also get damaged or loosen over time.

This hampers the battery’s proper charging capability. 


First, check if the connection cable and wire harness are in the proper place and tighten them in the right places. If the wires seem damaged by corrosion, you need to change them as soon as possible.

It’s common for wires to get corroded in such places as they are often exposed to moisture.

But if these two situations are not the case for your tractor, then it might be the battery itself. If that’s the case you need to replace the battery.

Problem 2: Slow or No Crank of Starter Motor

The starter motor cranks the engine during ignition and starts the rest of the process. The whole system might fail if the starter motor is malfunctioning.

There are several reasons behind the starter motor not working or failing to work at full capacity. 


Low battery voltage stops the starter motor from properly cranking enough to start the engine. The defective battery and damaged wire harness don’t allow the battery to keep charging for a long time.

As a result, the starter motor doesn’t get enough power to crank. Sometimes, the motor becomes worn out or defective, creating this no crank or slow crank problem. 


If the battery voltage is low, then simply recharge the battery. However, the defective battery needs to be replaced altogether. 

In case of a defective electrical wire harness, check the damage, and depending on the damage, you can either repair or replace it.

If there’s any corrosion on the wire, it is better to replace it altogether than clean it simply. The defective starter motor needs to be replaced as well.

John Deere 4040 Hydraulic Problems

Problems Reasons Solution
Hydraulic System Overheating due to John deere 4040 Hydraulic Problems  Improper hydraulic system pressure setting.  

Defective Main relief valve. 

Dirty hydraulic oil.

Air enters the hydraulic system. 

Set the pressure.

Replace relief valve.

Oil must be changed.

Check the suction line, pump seals, and fittings.

Hitch Problems Hydraulic fluid contaminated, Low fluid pressure.

Worn-out Hydraulic pump.

Dirty Oil filter.

Refill with fresh fluid.

Restore/replace the pump.

Change the oil filter to solve the John deere 4040 Hydraulic Problems.

Problem 1: Hydraulic System Overheating

Overheating of any parts of a vehicle, in general, is a serious issue. If the temperature gets too high, it can easily lead to hydraulic pump failure. And this can potentially damage the whole system.


Improper hydraulic system pressure mostly causes overheating of the hydraulic system. But the damaged relief valve can create this issue too. Sometimes, the hydraulic oil gets dirty, and air enters the hydraulic system, which can also create this issue.


To stop the air from getting into the system, you need to check for any leaks in fittings, pump seals, and suction lines and repair them.

But if the hydraulic oil is dirty, you must drain the rest of the oil and refill the compartment with fresh oil.

Check the tractor’s manual to see which pressure system is recommended for your own model and adjust it accordingly. You might need to buy a new relief valve and reinstall it if it has several damaged parts.

Problem 2: Hitch Problems

Three separate arms are used to make a three-point hitch, and each arm has a very specific purpose.

The hitch itself won’t move as easily or smoothly as you may think if one of them begins to malfunction.


A couple of different things can cause the hitch problem from time to time. But usually, it is the hydraulic fluid.

Sometimes there’s a lack of enough hydraulic fluid, while other times, there’s enough fluid, but it gets too cold because of the weather.

But then again, the hydraulic pump itself gets worn out, and the filter also gets dirty and causes the hitch to malfunction. The air can also get into the hydraulic system and cause malfunctions.


In the case of hydraulic fluid, it is better to drain the contaminated fluid.

To check if the transmission fluid is contaminated, you need to take a sample from the fluid reservoir and see if it matches the manufacturer’s recommendation.

Change the transmission fluid completely if the fluid is contaminated. If it is not up to the recommended amount, refill it with fresh fluid. 

You need to check the pump seals, suction pipe, and fittings to see if there are any air leaks and repair them with putty. But sometimes, depending on the leak, you might need a complete replacement.

If the pump doesn’t work, it’s better to replace it. You also need to replace the oil filter.

John Deere 4040 Transmission Problems

Problems Reasons Solutions
Hard Shifting of Gears in John Deere 4040 Transmission Problems Broken Shift gear.

Improper Clutch Adjustment.

Worn out Shift Fork.

Broken gear shift needs replacement.

Install new shift Forks.

Low Transmission Oil Pressure Faulty relief valve.

Low oil level.

Faulty Oil Filter.

Install new relief valve.

Refill Oil. 

Replace oil filter.

Noisy Transmission Broken shift gear & forks, bearings.

Low transmission Oil.

Contaminated transmission Oil.

Replace shift forks, bearings & gears.

Refill the oil compartment.

Refill with fresh oil.

Transmission Oil Leakage Damaged gaskets or seals, transmission case Replace the damaged parts to solve the John Deere 4040 Transmission Problems.

If you notice any jerks while shifting gears, this is a sign that your transmission needs to be repaired. 

Problem 1: Hard Shifting of Gears 

One of the worst transmission problems is when gears get hard to shift. A couple of different reasons are behind this problem.

But to find them, you need to check all of the possible reasons behind them. 


Stuck or broken gear shift linkage and improper clutch adjustment can easily make the gears harder to shift. Moreover, the gear shift mechanism and the shift forks get worn out over time. 

During the winter, the transmission fluid easily gets thickened, making it harder to shift the gears. 


For the improperly adjusted clutch, you need to remove them first and replace them back in their proper place. You can take instructions from your tractor’s manual book if it seems confusing.

Broken gear shifts often need replacement, as they are hard to repair. But if the damage seems small, you can try repairing it.

But there is usually no repair for shift forks. You need to buy a new one from the store and install it. These will only cost you $5-$7 per piece.

Problem 2: Low Transmission Oil Pressure

Low transmission Oil pressure indicates that there’s a low level of pressure overall. This indicates that your transmission takes longer than usual to engage when you shift gears.


The relief valve and the incorrect oil pressure can cause this issue. Over time it’s very common for your relief valve to get damaged, and the valve fails to create a good enough pressure that is needed for proper transmission.

And because of the faulty valve, it is very common for the oil level to be low. As the valve doesn’t release at the right time and too much oil gets used in one transmission.

Furthermore, if your tractor has a transmission oil filter installed, it can get dirty over time and cause low pressure.


Before refilling the transmission oil, ensure your relief valve is not damaged. Otherwise, you will be short of transmission oil and face low transmission oil pressure. 

If the valve is damaged, remove the connections and the old relief valve. Replace it with a new relief valve and put the connections back in. (our pick: Tractor Hydraulic Relief Valve)

In case of a clogged oil filter, you need to change it. These oil filters are widely available in hardware stores and online.

Problem 3: Noisy Transmission 

If you notice any unusual gurgling or knocking noise while shifting gears, it usually means that your transmission fluid level is lower than usual.

Transmission oil of the right grade and right type is really important for smooth transmission,

But other than low oil pressure, some parts can also be broken. Let’s check what is causing this noisy transmission.


Along with low transmission oil, the transmission oil can also get contaminated. The bearings of transmission shifts can get broken or worn out as well.

This can easily cause noisy transmission. Similarly, the damaged shift forks and gears cause noisy transmission as well.


You need to check each of these parts carefully to see which of the above reasons is behind your noisy transmission. If the oil level is lower than expected, fill it with fresh transmission oil. 

But if the transmission oil seems contaminated, before refilling the tank, drain all of the oil and then fill it up with fresh transmission oil.

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In case of broken or damaged bearings, gears,  and shift forks, replacing them is the best way to solve the noisy transmission problem.

Problem 4: Transmission Oil Leakage

It’s quite common for oil to leak,  but the reason behind it is not just the damaged tank or oil compartment. Let’s take a look at that other reason here-


Along with damaged oil compartments, your tractor’s gasket or seals can get worn out over time. Moreover, the transmission case gets severely cracked due to the heavy use of a tractor.


If the oil compartment is damaged, it’s better to take it to the garage for professional help. But the worn-out gasket and seals can easily be replaced within 10-50$.

But the transmission case might require a little more money and professional help. You can find transmission cases for around 400 to 800 dollars.

John Deere 4040 Steering Problems

Before we move onto details about the type of steering problems and the reasons behind them here’s an overview of the whole situation:

Problems Reasons Solution
Heavy Steering cuased by John Deere 4040 Steering Problems Defective Steering column.

Steering system oil leak.

Insufficient Steering fluid.

Worn-out valve assembly.

Defective steering pump.

Correctly install steering column.

Recheck hose and steering line connection.

Repair the slight defects of valve assembly & steering pump.

Excessive Steering Wheel Play Damaged Hydraulic steering pump.

Defective Steering linkage or tie-rod.

Damaged Steering column Coupling or Shaft, valve assembly.

Repair or Replace Steering pump.

Replace damaged part of the steering tie-rod.

Replace worn out shaft or component of the valve assembly.

Tractor Pulled to the right or left Incorrect Toe-in adjustment and front hub bearing.

Faulty tie-rod ends and damaged steering valve assembly.

 Incorrect inflation of tires.

Replace/ adjust toe-in and the bearings correctly.

Change damaged component.

Inflate tires properly to solve the John Deere 4040 Steering Problems. 

Problem 1: Heavy Steering 

Heavy steering is one of the worst steering problems to face while driving a tractor. With heavy steering, it gets harder even to turn your vehicle. 


A faulty steering column is one of the main culprits behind heavy steering. Steering system oil leaks and insufficient fluid also cause serious steering issues.

Along with this, sometimes tires that are deflated can create steering problems. Worn-out valve assemblies and a defective steering pump also cause this.


Although all of these reasons create the same heavy steering issue, each requires different fixes.

Replacing the defective steering column and steering pump is the best step. But repairing can be an option if the damage is small.

In case of an oil leak, you need to recheck the hose and steering line connections and tighten them. It is obvious to inflate deflated tires to get them working again.

Fill the steering fluid up to the required level to get the steering column to move more smoothly. And for worn-out valve assembly, you can repair the slight defects, but it’s better to replace them.

Problem 2: Excessive Steering Wheel play

A tractor’s steering is connected to its steering knuckles through ball joints. Usually, when these ball joints come to lose, it creates an excessive steering wheel play problem. 


Generally, the hydraulic steering pump is worn out or damaged, which is behind this annoying problem.

But the steering column shaft or the coupling can easily get loose as well. Mostly, this is because of excessive use over time.

Moreover, the steering valve assembly and tie rods get defective as well. All of these components hold specific parts. If one comes loose, then it can easily cause the steering to move left and right uncontrollably.


It is best to replace these parts for these excessive steering wheel play problems. Damaged hydraulic steering pumps can hardly get repaired, so it’s better to replace them professionally.

Defective steering valves or tie-rod ends can be a less costly replacement but necessary.

Similarly, the coupling or the shaft can be easily replaced for the steering column. You can easily find them on amazon or your nearby repair shop. 

Problem 3: Tractor Pulling Left or Right

Tractors pulling left or right is an unusual problem but one of the most common. Although this problem has detected reasons behind them, one might easily overlook them.


Incorrect Toe-in adjustment and front hub bearing can easily make the tractor pull left or right uncontrollably.

Faulty tie-rod ends and damaged steering valve assembly can also cause this issue. Sometimes incorrect inflation of tires can cause this as well.


First, thoroughly check all these components to detect which might be the reason for your vehicle malfunction. Tires can be incorrectly inflated by pushing too much or too little air.

If the former is the case, then you need to remove some air pressure and for later cases, simply add more air to the tire.

 And for incorrectly installed toe-in adjustment and front hub bearing, you might require professional help to reinstall.

Worn-out tie-rod end and damaged steering valve can be replaced if it isn’t beyond repair.

How Can You Avoid John Deere 4040 Problems?

You must follow some basic maintenance tips to keep your tractor up and running for a long time.

It might require you to add extra 15-20 minutes of work after fieldwork, but this will ensure your tractor is in good condition with almost no extra cost.

  • Every day after 10 or more hours of fieldwork, check the air cleaner and oil level in the engine. Make sure there’s enough oil and no amount of damage done.
  • But do this inspection at least 15 minutes after you have turned the engine off. While doing daily checkups, refill the water level of the radiator per requirement.
  • Weekly check your tires’ air pressure and drain out the water stored in the oil filter. Keep the water level of the battery at the right limit. Make sure to use grease on the bearings, brake control, tie rod, clutch shaft, etc, to keep them working properly.
  • Every two weeks, apply oil to the tractor’s starter and dynamo. You also need to clean the smoke tube. Usually, carbon dirt builds up on this tube from time to time.
  • Every 4 weeks, after around 250 hours of fieldwork, clean the primary diesel filter or change it if there’s any significant damage.
  • Make sure to change the drain oil from the gearbox and fill it up with fresh and clean right grade oil every 6 months.


That concludes our discussion about John Deere 4040 problems. It is quite common for your tractor to have steering or engine problems from time to time.

But with proper maintenance, you can ensure 4000 hours of fieldwork from your tractor without facing too many issues.

If you face issues that seem difficult to solve with basic knowledge, don’t hesitate to ask for professional help.  

And we are always here to help you with any problems, so comment below with any query. Until next time!

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