The part(s) or condition(s) listed below for the symptom Pressure washer leaking water are ordered from most likely to least likely to occur. Check or test each item, starting with the items at the top of the page.
You may need to rebuild or replace the pump assembly. If the pump is more than a few years old, and you use the pressure washer fairly often, replace the pump assembly. If the pump is relatively new, and you don’t use the pressure washer often, either rebuild the pump assembly or replace the pump seals.
Himore 3100 PSI Vertical Pump, 2.5 gpm. This pump has been improved by the manufacturer and may differ in appearance from the original. The new pump does not require you to add grease or oil. When installing this pump, you must reuse your thermal release valve and drive key or purchase new ones.
The leak could be due to the normal operation of the thermal release valve. The thermal release valve allows hot water to exit the pressure washer if the water temperature becomes excessively high. If the pressure washer is left running while it is not spraying water, the water in the pump will begin to heat up. When the water temperature rises above the acceptable limit, the thermal release valve opens to allow the hot water to exit the pressure washer.