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De Walt Pressure Washer Problems: Pump & Water Troubleshooting With Fixes

De Walt pressure washers are an excellent choice for cleaning your house’s driveway, patio, and all kinds of flooring. However, as with any machine, there is always the chance that it does not work as it should. In the case of these pressure washers, minor hiccups with the pump or water delivery system can occur for various reasons.

De Walt Pressure Washer Problems. Pump & Water Troubleshooting.

If your De Walt pressure washer leaks water, the problem might be with the pump or the connections at the intake hose, high-pressure hose, and spray gun. Check that all the connections are tight and that the seals and O-rings are in good condition. If you observe an unusual change in water pressure, inspect the nozzles and ensure the unloader valve is set correctly. If your pump is leaking oil or making different sounds, you should lubricate it and get its seals inspected.

If you own a De Walt Pressure washer, I always recommend knowing how to troubleshoot your pressure washer if problems occur. In this article, I will explain the root cause of various De Walt problems and how they can be fixed.

De Walt Pressure Washer is Leaking Water

Water might leak from the pipe connections on your De Walt pressure washer. Check the connections at the pump and spray gun separately to determine the source of the water leak.

A leak is more likely to occur in one of three places. The pump might be the source of the leak, and the pump’s intake and exit hose connections are other locations where a leak might develop. Water can also escape from the spray gun’s connection to the high-pressure hose.

● De Walt Pressure Washer: Water Leaking from the Pump

If your De Walt pressure washer leaks directly from the pump, the piston seals are most likely worn out and must be changed.

Most pressure washer pumps have a piston mechanism with positive displacement to pump water through the hoses. A piston seal prevents water from leaking out of the pump. These seals are prone to degradation with time, which might contribute to a leak. In that case, you may need to disassemble the pump case and examine for signs of wear on the piston seals.

This applies only if you have a plunger pump. Axial and wobbling plate pumps are factory assembled and cannot be disassembled for repairs. As a result, in such a case, seals cannot be replaced individually, and the whole pump must be replaced to fix the issue.

● De Walt Pressure Washer: Water Leaking from the Hose Connection

If the hose connections on your pressure washer leak, the fittings at these attachments have worn out and should be changed.

A connector/pipe connection links the hose to the pump’s low-pressure input and comes with a leak-proof seal. If there is a leak at that location, the connection and seal are more likely to be damaged.  Similarly, if the connector between the pump’s high-pressure output and its corresponding hose leaks, you should replace the outlet seal.

● De Walt Pressure Washer: Water Leaking from the Spray Gun

Examine the hose-gun connection and adjust the screws if the spray gun on your De Walt pressure washer leaks. Furthermore, inspect the outlet of the high-pressure hose for a cracked O-ring and replace it if required.

Most pressure washers use a press fit to attach the high-pressure hose to the spray gun. Check it to ensure the fit is correct and the connection is not loose. Ensure that the screws are tightly secured. If the leak occurs after tightening the fit, please ensure that the O-ring at the hose is still there and is intact. A cracked or missing O-ring might have caused this leak.

Pressure washer seals, gaskets, and O-rings can be purchased online or via a pressure washer parts store.

De Walt Pressure Washer: Water Pressure Problems

If your De Walt pressure washer isn’t producing enough water pressure, follow the steps below.

● 1. De Walt Pressure Washer: Low Pressure

To fix low water pressure, ensure enough water is coming in and the inlet line is not clogged with dirt. Furthermore, ensure that the nozzle is not worn out or clogged.

The amount of water at the pump’s input must be sufficient to provide the required pressure. Inspect the input hose for twists or bends and remove them. Furthermore, most intake hoses feature a dust filter where it connects to the pump. Look for any dirt that has been trapped in the filter. If the pressure remains low, double-check that you’re using the correct nozzle and that it’s not blocked with debris.

● 2. De Walt Pressure Washer: No Pressure

If your pressure washer loses pressure, check the water supply, hoses, and nozzle. Next, inspect the unloader valve and the pump, at least one of which needs to be fixed.

Pressure loss can also result from nozzle debris or a low water supply. But in this case, the pump and unloader valve is most likely to be the fault. While the pump is running and the trigger is pushed, gently adjust the unloader valve to see if the pressure improves.

If the problem does not resolve, replace the unloader valve, which is almost certainly malfunctioning. You should also check your pump’s plungers and O-rings for damage.

Cavitation-induced air bubbles can cause long-term damage to various pump components, resulting in pressure loss. Consult the owner’s handbook before attempting to replace parts on your pump. Because most pumps are manufactured as entire units, they cannot be disassembled and must be replaced with identical units.

● 3. De Walt Pressure Washer: Surging Pressure

If your water pressure suddenly rises, check your nozzle for obstructions or signs of damage. Adjust the unloader valve, so more water runs via the bypass and less enters the spray gun.

The unloader valve of a pressure washer directs a portion of the high-pressure water flow to the pump intake or water tank instead of the spray nozzle. Very little incoming flow is bypassed when your unloader valve is set tightly, resulting in high pressure at the gun outlet.

Loosening the unloader valve would increase the flow rate across the bypass, reducing pressure spikes at the spray gun. If this does not work, inspect your nozzle for visible indications of damage and replace it if necessary.

● 4. De Walt Pressure Washer: Drops Pressure after a Few Seconds

If your water pressure suddenly drops, it might be caused by a worn-out nozzle or a hose leak. An incorrectly tuned unloader valve might also cause this issue.

In contrast to the last example of surging, if the unloader is set too loosely, the pressure at the spray gun may decrease. If this setting is too loose, even a small amount of flow may overcome the spring tension and flow to the water tank. As a result, the water pressure at the nozzle’s output decreases.

Apart from that, examine your hose for any holes or leaks. Moreover, also ensure that your nozzle is not clogged with dirt or debris.

● 5. De Walt Pressure Washer: Strange Noises from Pump

If your pump makes an unusual noise, it might be due to worn-out connecting rods or bearings. If it is not greased on time, it will also generate noise.

High-end pressure washers employ plunger-type pumps, which must be refilled with oil every three months. As a result, these pumps hardly demand regular maintenance. In low-end variants, the pump is either axial or wobbling plate type. Because they are permanently sealed with oil after production, these pumps do not require oil refilling.

– Solution

Depending on the pressure washer, the pump should be maintained and lubricated with oil every three months (axial or plunger). Metal parts tend to rub against each other when not lubricated, resulting in high noise. If this occurs, you should detach your plunger pump and inspect the bearings and connecting rods. A bearing replacement may be needed if lubricating the pump does not fix the problem.

If the noise is still there, the connecting rods of the pump could be faulty, especially if your pump is old. Fatigue and strain can accelerate the wear rate in your pump’s connecting rods, especially if it has been in use for a long time. 

If the axial or wobbling plate pump in your pressure washer produces strange noises, replace it with a similar pump since it cannot be repaired.

● 6. De Walt Pressure Washer: Excessive Noise

If your pressure washer generates a lot of noise, it might be because of broken internal pump parts, air entering the pump, a damaged pump casing, or the engine knocking due to poor fuel quality.

– Pump Wear & Tear:

When air becomes caught in a pump, the plungers make a loud grinding noise, which can wear down seals and connecting rods. If the pump’s casing gets damaged, it can create significant vibrations and noise.

– Engine Knocking:

Check the grade of the fuel entering the engine if you have a gas-powered pressure washer. I recommend using ethanol-free, unleaded gasoline with an octane number of at least 87 to avoid engine knocking. You may also consult your owner’s handbook for more information.

● 7. De Walt Pressure Washer: Oil Leaking from the Pump

A pump leaking oil has a faulty O-ring or a cracked seal. If necessary, dismantle your pump and replace all the seals by hand. Contact the manufacturer for assistance if the product is still under warranty.

If your pump can be disassembled and your warranty has expired, it can certainly be repaired. Hire a mechanic or contact your manufacturer if you lack the skills. I recommend getting an oil seal kit, which has seals and rings in various sizes, to help you with the replacements.

Check that all bolts and fittings are correctly tightened during reassembly. Never expose your pressure washer to high temperatures, as they can quickly destroy rubber components and may produce oil leaks in the future.

If the pump on your pressure washer is permanently sealed, the only solution is to replace the whole pump.

● 8. De Walt Pressure Washer: Water in Oil

If the oil seal on the pump breaks, water might enter the pressure washer. In this case, you should consider replacing the seal.

Because of the presence of water, the pump oil becomes milky. A malfunctioning oil seal might cause this. The pump must be entirely dismantled to replace the seal, including the housing, valves, seals, and rings.

I’d do this just after the pump’s warranty expires. If the manufacturer’s warranty still covers the pump, it should be repaired by the manufacturer or replaced as applicable. Only pressure washers with refill available such as plunger pumps are affected by this. Most low-cost pressure washers have a permanently sealed pump that must be replaced entirely if broken.

● 9. De Walt Pressure Washer: Soap Not Dispensing from Reservoir

Check the nozzle size if your pressure washer isn’t extracting soap from the reservoir. Additionally, you must inspect the soap injector kit and repair any broken or worn-out parts.

For the soap injection function, the owner’s manual suggests a specific type of nozzle that delivers enough suction pressure for all detergent types. Check that you’re using the correct nozzle. If it still doesn’t work, ensure that your injection kit’s nozzle isn’t clogged. A chemical injector repair kit can assist you by providing the requisite spare parts.

De Walt 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

● De Walt 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.

● De Walt 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.