Water Pump Maintenance
Pressure washer water pumps need relatively low maintenance. The two main concerns are keeping contaminants out of the pump and changing the pump oil on schedule. (Some pumps do not need oil changes.) Purge the water pump to remove impurities and debris and change the pump oil every 50 hours of use or once a year, whichever occurs first. Use only oil recommended by the manufacturer, as specified in the owner's manual. (Purchase pre-measured bottles of pump oil for water pumps without dipsticks.) Never use special oil additives or detergents, unless specified in the owner's manual.
Step 1 - Purging the pump of contaminants. Prepare the pressure washer for use. Turn on the supply water, then remove the wand from the spray gun. Start the engine, then squeeze and hold the spray-gun trigger until there is a constant, steady stream of water. Hold for 2 minutes, then engage the trigger safety latch and refasten the wand to the spray gun.
Step 2 - Changing pump oil. Drain the oil and fuel from the engine. Remove the oil cap on the water pump with an Allen wrench. Tilt the pressure washer to drain the used oil into an approved container. Tilt the unit back in the opposite direction after the oil has drained.
Step 3 - Changing pump oil. Fill the water pump with fresh oil, following the directions in the owner's manual. Note: Premeasured bottles of water pump oil are available for some models. Reinstall the oil cap and tighten firmly, then wipe up any excess oil around the cap and set the pressure washer in the upright position. Clean up any spilled oil, and dispose of used oil and soiled rags in accordance with local environmental statutes.
See also: Preventative Pressure Washer Maintenance