Pressure washer leaking water: Common Causes & How to Fix
1Pressure Washer Pump Assembly
Most Common Solution
Repair Instructions:
You might need to rebuild or replace the pump. If the pump is older and you use the pressure washer a lot, just replace the whole pump. If the pump is still pretty new, and you don't use the washer much, try rebuilding it or swapping the seals. How old the pump is and how often it gets used impacts the repair. An older, frequently used pump is probably too worn out for rebuilding. Replacing it ensures you get back to full pressure. If the pump hasn't run much yet, rebuilding could work. But new seals may be needed either way. Try fixing a newer pump first before complete replacement. But an old pump that gets heavy use will need a full swap out to fully restore pressure washing power.
How to Replace Pressure Washer Pump Assembly
- Shut off water supply and disconnect hoses. Turn off the water supply to the pressure washer and disconnect the water inlet and outlet hoses. This will drain any remaining water from the pump assembly.
- Disconnect wiring. Locate and disconnect any electrical wiring connected to the pump motor. This usually includes disconnecting the power cord.
- Remove pump assembly. The pump assembly is usually held in place with mounting screws or bolts. Remove all fasteners to fully detach the assembly. Lifting up and out once detached.
- Inspect pump and supply lines. Check the pump seals, valves, and supply lines for any wear or damage. Replace parts as needed.
- Install new pump assembly. Place the new pump assembly into mounting location and reinstall the fasteners. Connect water inlet and outlet hoses.
- Reconnect wiring. Plug in or reconnect any electrical wiring to the pump motor. Double-check connections.
- Restore water supply. Turn water supply back on and check for leaks. Let water run through the pump briefly to check operation.
- Test operation. With all hoses reattached, power on and test operation of pressure washer. Check water pressure and flow. Ensure no leaks.
2Pressure Washer Pump
Most Common Solution
Repair Instructions:
You might need to rebuild or replace the whole pump piece. If the pump is older and gets used a lot, just swap in a new one. If it's still pretty new, and you don't use the washer much, try fixing the pump or replacing the seals. How old it is and how often it runs impacts the repair. An older pump that gets heavy use is probably too worn out to rebuild. Replacing the whole pump ensures full pressure is restored. If it hasn't run much yet, rebuilding could work. But new seals may be needed anyway. Try fixing a newer pump first before total replacement. But an old, frequently used one will need the full assembly swapped out to get back to full power washing abilities.
How to Replace Pressure Washer Pump
- Shut off water supply and disconnect the hoses. Turn off the water supply to the pressure washer and disconnect the water inlet and outlet hoses from the pump. This will drain any remaining water.
- Disconnect wiring. Locate and disconnect any electrical wiring connected to the pump motor. This usually includes disconnecting the power cord.
- Remove pump mounting hardware. The pump is usually mounted with screws or bolts. Remove all fasteners to fully detach the pump.
- Remove pump. Once detached, lift the pump out of the pressure washer frame.
- Install new pump. Place the new pump into the mounting location and reinstall fasteners to secure it in place.
- Reconnect hoses. Reconnect the water inlet and outlet hoses to the pump. Use thread seal tape to prevent leaks.
- Reconnect wiring. Plug in or reconnect the electrical wiring to the pump motor. Double check connections.
- Restore water supply. Turn the water supply back on and check for leaks. Allow water to run through the pump briefly.
- Test operation. With all hoses reattached, power on the pressure washer and test operation. Check water pressure and flow to ensure proper functioning.
3Pressure Washer Thermal Release Valve
Common Solution
Repair Instructions:
The leak might be from the thermal release valve working normally. That valve lets hot water escape if the temperature gets too high inside. When the washer runs but isn't spraying, water in the pump starts heating up. If it goes over the safe limit, the valve opens to release the hot water. This prevents damage from excess heat buildup. Letting the pump run while not spraying can trigger the valve. The water has nowhere to go, so it sits and gets hotter. Once it reaches the cutoff temperature, the valve has to open and discharge the scalding water. This protects the internal components. So some leakage means the thermal valve is just doing its job and preventing overheating issues. It should stop once spraying resumes and the water temperature decreases back to normal.
How to Replace Pressure Washer Thermal Release Valve
- Locate the thermal release valve. The valve is usually found on the discharge side of the pump. It may be connected via a hose or threaded directly into the pump housing.
- Shut off water supply. Turn off the water supply to the pressure washer. This allows the valve and lines to depressurize.
- Disconnect hoses/fittings. Use pliers to loosen and remove any threaded fittings connecting hoses to the valve.
- Remove valve. Unthread the valve from the pump housing if threaded. Some valves are held in by a retaining clip that needs removed.
- Inspect valve and seat. Check valve seat for debris, damage, or wear. Clean or replace as needed.
- Install new valve. Thread the new valve into the pump housing until tight. Or insert and replace the retaining clip.
- Reconnect hoses. Reattach any hoses to the valve using thread seal tape on connections.
- Restore water supply. Turn the water supply back on and check for leaks.
- Test operation. Allow the pressure washer to run and check that the new valve opens and releases water when the predetermined temperature/pressure is reached.