Pressure Washer Pump

A pressure washer pump is one of the main components of a high-powered pressure washer used by both homeowners and professionals alike. The pump is the part that drives the entire system, for without it the water would not become adequately pressurized to be effective. When properly maintained, a pressure washer pump will stay relatively trouble free. In most cases, when a problem arises with a pressure washer, it is usually not the pump to blame. Still, pumps may need replacing and are available as aftermarket parts. 

Pressure Washer Pump Specifications

While some pressure washer pumps may be designed for a specific make and model, many pumps are universal in application provided the specifications match up. Pressure washer pumps mount to the washer with a steel faceplate. The number of bolts used to attach the pump in part determines a pump's usability. Pumps are designed for use with motors of a particular horsepower. For instance, Comet makes a 4-bolt pump that works with 5 to 6.5-horsepower motors. Other key specifications include the maximum PSI and gallon-per-minute flow rate. The diameter of the shaft or cylinder varies as well and affects the flow rate. The shaft diameter is commonly 3/4 of an inch. 

Pump Varieties

Pressure washer pumps may be gas fueled or electric. Cold-water pressure washers are less involved, as they only require electricity or fuel to power the pump and the motor. Hot-water pressure washers are more complex tools that also include a burner and a heating coil to superheat inflowing water. 


Expect to spend between $100 and $400 on a replacement pressure washer pump. Different pump specifications are the main reasons for the disparity in prices. Universal pumps are available, designed to fit a wide variety of pressure washers. Factory-made replacement pumps are another option. Before replacing the pump, be sure it is to blame for a malfunctioning pressure washer, for it might very well be a worn-out nozzle.