Skip to Content

John-Deere Pressure Washer Problems: Pump & Water Troubleshooting With Fixes

John-Deere produces a wide range of pressure washers for domestic and industrial cleaning. Although these machines are pretty rugged, users can occasionally experience issues such as water leaking from somewhere or pressure variations (either too high or low). These problems are generally associated with a pressure washer’s pump or water supply network.

John-Deere Pressure Washer Problems:

If your John Deere pressure washer leaks water, the pump, input hose, high-pressure hose, or spray nozzle could be faulty. Check that all connections are tight and the seals are secure and in good working condition. In case of significant variations in water pressure (too low or too high), you should examine the spray nozzle and ensure that the unloader valve is correctly set. If the pump produces an unusual noise or leaks oil, inspect the seals for damage and make sure the pump is being lubricated timely.

Since most users aren’t accustomed to troubleshooting a pressure washer on their own, this article shall help them diagnose the root cause of the problem and fix it themselves.

John-Deere Pressure Washer is Leaking Water

If your John Deere pressure washer leaves a lot of water beside it, check the hose connections at the pump intake, spray gun, and pump itself. Check if any of these locations have a leak developed.

A leak is more likely to occur at one of these three locations. Water may leak if the intake hose’s seal is damaged. The connection between the high-pressure line of the pump and the spray nozzle is prone to leaking. Furthermore, if the pump’s seals are compromised, water could leak from here too.

● John-Deere Pressure Washer: Water Leaking from the Pump

If your John Deere pressure washer leaks straight from the pump, the piston seals must be replaced.

Most pressure washer pumps have a piston mechanism with positive displacement to pump water via the hoses. A piston seal keeps water keeps water from entering or leaving the pump. These seals weaken with time, resulting in a leak. In this case, removing the pump casing and inspecting each piston seal for signs of wear may be required.

This procedure can only be carried out if you have a plunger pump. Axial and wobbling plate pumps are assembled permanently at the factory and cannot be dismantled for maintenance or repair. As a result, their seals cannot be replaced individually; the whole pump must be rebuilt to fix the problem.

● John-Deere Pressure Washer: Water Leaking from the Hose Connection

If your pressure washer’s hose connections are leaking, you must replace the pipe fittings or couplings at these locations.

A pipe connector connects the pipe to the pump’s low-pressure input, and a seal prevents a leak. If there is a leak, the connection is loose, or its seal has most likely failed. Similarly, if a leak forms at the pump’s high-pressure output and its accompanying hose, the pump’s exit seal must be inspected and replaced if it’s damaged.

● John-Deere Pressure Washer: Water Leaking from the Spray Gun

If your John Deere pressure washer’s spray gun leaks, inspect and tighten the hose-gun connection. Examine the high-pressure line’s outlet for a damaged O-ring and replace it if required.

A push fit connects the high-pressure hose to the spray nozzle on most pressure washers. Check that the connection is secure and of the proper size. Check the tightness of any screws that are present. If the leak continues after tightening the fitting, ensure the hose’s O-ring is intact and present. A missing or cracked O-ring might have caused this leak.

Seals, gaskets, and O-rings for pressure washers are available at local stores and online.

John-Deere Pressure Washer: Water Pressure Problems

If your John Deere pressure washer does not consistently produce adequate water pressure, I recommend following the steps below.

● 1. John-Deere Pressure Washer: Low Pressure

To fix low water pressure, ensure enough water enters the pump, and the input line is not blocked with debris. Also, ensure that the spray nozzle is not damaged or clogged.

The amount of water entering the pump must be sufficient to create enough pressure for pressure washing. Also, it would be best if you eliminated any curves or bends in the input line to avoid back pressure on the pump. A dust filter is present in most input hoses at the pump connection. Examine and clean the filter after enough dust accumulation. If the pressure remains low, ensure that the correct nozzle is being used and that it is free of debris.

● 2. John-Deere Pressure Washer: No Pressure

If the output pressure of your machine drops, check the water supply, hoses, and nozzle. At least one of the unloader’s valves or pumps will need troubleshooting.

A clogged nozzle, insufficient water supply, and nozzle debris may also cause pressure loss. In this case, the pump or unloader valve is most likely to blame. Adjust the unloader valve while the pump runs, and the trigger is pushed to see whether the pressure has risen.

If the issue continues, the faulty unloader valve must be replaced. It would be best to inspect the pump’s plungers and O-rings for damage.

Another factor contributing to the problem could be cavitation in the pump. Cavitation may develop in air bubbles, causing damage to pump components and a pressure reduction over time. Before changing any pump components, see the owner’s handbook. Since most pumps (axial or wobble plate type) are built as a single unit, they cannot be disassembled and must be replaced with similar ones.

● 3. John-Deere Pressure Washer: Surging Pressure

If the water pressure suddenly rises, inspect the nozzle for clogs or signs of damage. Adjust the unloader valve so that a large quantity of water enters the bypass while a small amount enters the spray nozzle.

The unloader valve on a pressure washer redirects a portion of the high-pressure water flow away from the spray nozzle and into the pump intake or water tank. When the unloader valve is tightened, a tiny fraction of the incoming flow is bypassed, resulting in a high output pressure at the nozzle.

The bypass flow rate rises when the unloader valve is set to a comparatively loose position. Spray gun pressure spikes are reduced as a result. If this does not solve the issue, inspect the nozzle for visible indications of damage and replace it according to the manufacturer’s instructions.

● 4. John-Deere Pressure Washer: Drops Pressure after a Few Seconds

A faulty nozzle or a leaking hose might be the source of a sudden drop in water pressure. A faulty unloader valve might have aggravated this problem.

The spray gun pressure may decline if the unloader is set too loose, unlike in the prior case of surging. If you make this adjustment too loose, the flow will surpass the tension of the spring and enter the water tank. As a result, the water pressure at the nozzle’s exit decreases. In addition to this modification, inspect your hoses for holes and leaks. Make sure the nozzle is clean and clear of debris.

● 5. John-Deere Pressure Washer: Strange Noises from Pump

The connecting rods or bearings may wear out if your pump makes strange sounds. Unwanted noise is also generated due to insufficient pump lubrication.

Oil must be replaced in premium pressure washers with plunger-style pumps every three months. For these pumps to function correctly, they must be serviced regularly. The pump in low-end variants is either an axial or a wobbling plate. Because these pumps are permanently injected with oil during manufacturing, they do not need lubrication after a certain amount of time.

– How to Repair?

Depending on the kind of pressure washer, the pump should be maintained and oiled every three months (axial or plunger). Metal components not lubricated tend to rub together and produce a lot of noise. If this happens, dismantle the plunger pump and inspect the bearings and connecting rods. If lubricating the pump does not solve the problem, replacing the bearings on your pump may be necessary.

If the noise continues, particularly if the pump is old, the connecting rods may be faulty. Fatigue and tension may hasten the wear of connecting rods, particularly if used for long periods.

If your pressure washer’s axial or wobble plate pump is making odd sounds, you must replace it with an identical pump since it cannot be fixed in the same way as described above.

● 6. John-Deere Pressure Washer: Excessive Noise

If your pressure washer makes a louder noise than usual, it might be due to damaged pump components, air entering the pump, a cracked pump casing, or an engine knocking due to low fuel quality.

– Pump Casing:

If the pump’s casing is broken, vibrations and undesirable noise could get aggravated. A loud grinding sound may be created if air bubbles get lodged in the pump. This might damage the pump’s seals and connecting rods.

– Engine Knocking Sound:

Check the fuel quality if the engine of your gas-powered pressure washer is knocking. To avoid engine knocking, I suggest using ethanol-free, unleaded gasoline with a minimum octane value of 87. You might also consult the owner’s handbook for further information.

● 7. Briggs & Stratton Pressure Washer: Oil Leaking from the Pump

If the O-ring or seal is broken or faulty, the oil may flow from the pump. After dismantling the pump, replace each seal by hand if necessary. Contact the manufacturer for a replacement if the product’s warranty is still intact.

If the warranty on your pump has expired, you are free to dismantle it yourself. Consult a mechanic if you lack the necessary tools and skill level. To help with the replacements, I recommend purchasing an oil seal kit with various seals and rings.

Check that all fasteners and fittings are securely tightened before reassembling. Never expose your pressure washer to high temperatures to prevent further oil spills. In the case of axial or wobbling plate pumps, the sole remedy is to replace the pump.

● 8. John-Deere Pressure Washer: Water in Oil

If the oil seal on the pump is compromised, water may enter the pump. In this situation, consider replacing the seal.

The milky appearance of pump oil, caused by water, indicates a compromised oil seal. To replace the seal, you must entirely remove the pump’s casing, valves, and rings.

I will only do this if the pump’s warranty is no longer valid. If the pump is still under warranty, the manufacturer will repair or replace it. Only pressure washers with replaceable pump oil, such as plunger pumps, undergo the above problem. Because most low-end pressure washer pumps are permanently sealed with oil, they should be replaced completely if they fail.

● 9. John-Deere Pressure Washer: Soap Not Dispensing from Reservoir

Check the nozzle size if your pressure washer isn’t pulling soap from the reservoir. Examine the injector kit’s components for wear or damage.

The owner’s handbook recommends a nozzle for the soap injection function that provides sufficient suction pressure for all kinds of detergent. Check that the proper nozzle is being used. If the issue continues, ensure the injector’s nozzle is not clogged. I’d consider buying a chemical injector repair kit with all the essential replacement components.

John-Deere Pressure Washer troubleshooting table:

The pressure washer is not producing high pressure
Hose with small diameter
Replace your hose with a 1″ (25mm) or 5/8″ (16mm) hose
Restricted water supply to the washer
Check for the kinks and leaks in the hose
Inadequate water supply
Ensure the water source is unobstructed and fully turned on
Clogged intake filter
Remove the filter and rinse it with warm water
Air in the pump
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
The suction tube or detergent bottle is not connected properly
Install the suction tube and detergent bottle correctly
Detergent too thick
Dilute the thick detergent by adding water
Obstructed spray tip
Remove the debris with a needle
No pressure tip on the wand
Install a suitable pressure tip at the end of the wand
If your model has a belt, it can be loose.
Tighten or replace the belt.
Pulsing pressure washer (output pressure varies high and low)
Inadequate water supply
Ensure that the water source is fully on and check the hose for kinks and blockage
Obstructed spray tip
Remove the debris with a needle
Pump sucking air
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
Clogged intake filter
Remove the filter and rinse it with warm water
Calcified hose, tip, or trigger
Clean the hose, pressure tip, or trigger with vinegar or a cleaner designed for this purpose
Noisy Pump
Air in the pump
Ensure that the hose and fittings are airtight. Shut off the washer and squeeze the trigger until water flows steadily from the spray tip
Clogged inlet filter
Remove the filter and rinse it with warm water
Pump leaking water
Damaged or worn water seals
Replace the seals with new ones or call a professional
Loose fittings
Ensure that all the fittings are tight
Erratic water pressure, changing up and down
Unloader valve
Check and clean the unloader valve. If in bad shape, replace it
No output pressure. Or the motor stops when using the trigger (electric models)
Unloader valve
Check and clean the unloader valve. If in bad shape, replace it

● John-Deere Electric Pressure Washer Motor troubleshooting table:

The motor won’t start
The power switch is in the “OFF” or “0”  state
Turn the power switch “ON” or “1”
Cord not plugged
Plugin the power cord
Damaged, too long, or improper extension cord
Replace the existing cord with a 25′ (7.6m) 14 AWG cord or a 50′ (15m) 12 AWG cord
Inadequate power from the electrical outlet
Plug the cord into a different outlet
The pressure washer circuit breaker tripped
Please wait for the washer to cool down and restart it
The motor buzzes but fails to run
Loss in voltage due to the extension cord
Plug the unit directly into the outlet without an extension cord. If the problem isn’t solved, replace the extension cord
Low supply voltage
Ensure that only the pressure washer runs on that circuit at the time of use
Residual pressure in the system
Shut off the washer and squeeze the trigger to release pressure
Residual friction among the internal components
Cut the water supply and turn the machine ON for 2 to 3 seconds. Try it a couple of times or until the motor starts. Don’t let the machine run dry for more than 3 seconds.
Unit not used for long periods
I recommend calling a professional for help
Motor not working
Faulty Timer
Disconnect the leads from the timer. If your pressure washer doesn’t turn off after the time out, the timer is faulty, and you need to replace it.

● John-Deere Gas Pressure Washer Engine troubleshooting table:

Leaks in the spray wand, spray tip, or extension
Damaged or broken O-rings or plastic insert
Replace the worn O-rings or call a professional
Pressure washer pump dripping oil
Worn or damaged oil seals
Inspect the oil seals and replace them if worn
No water from the washer outlet
The water supply is off
Turn the water supply ON
Kink in the hose or faucet not fully open
Remove any kinks and debris from the hose or water lines. Check and fully open the faucet.
The motor won’t start
Check the battery
Check if the battery is charged correctly. Charge or replace when in bad condition. Examine the battery terminals for a proper connection. Clean if needed.
Check the fuel filter
Clean the fuel filter if dirty. In that case, check the gas tank, as this is the most likely culprit.
Check the gas supply
Check the fuel level and add if needed. Ensure that the gas can flow to the carburetor. Remove any blockage.
Check the Air-filter
Clean the air filter. Replace it when it is in bad condition or it is a paper air filter.
Check the carburetor
Remove and clean the carburetor with some carb cleaner. It is also possible to clean it without removing it.
Fuel gap blocked
Check that the hole in the fuel cap is open. Clean if needed.
The engine is stalling, or starts and stops
Check the carburetor
Remove and clean the carburetor with some carb cleaner. It is also possible to clean it without removing it.
Air filter
Clean the air filter. Replace it when it is in bad condition or it is a paper air filter.
Check for bad gas
Suppose you have old gas, more than a few months old. It can turn bad. Drain and replace the gas. Next time add a fuel stabilizer.

Leave a comment

Please read our comment rules first here. Your email address will not be published. All fields are required.

  1. Sandra Austin says:

    Does the article address the scenario where water is found in the oil of a John Deere pressure washer?

    • Allard Vdhooft says:

      Hi Sandra, the blog post provides troubleshooting tips for water leaking from a John Deere pressure washer. Check hose connections for leaks, replace seals as needed. Hope this helps!