I bought a pressure washer at a garage sale for 5 bucks, and was told that the washer worked, but the pump didnt. I cleaned out the old gas and cleaned the carb, filled with new gas and the motor runs fine. The problem is that the pressure surges (pressure, no pressure, pressure, no pressure.....in quick increments). So I took the pump off, and everything internally looks fine. No wear or cracks in the housing, and the valves look good also.

My question is....what do they use inside these pumps to cool them? On a fire truck, we use regular coolant to cool the pumps....but I am not sure if that is what they use on a smaller pump. Does anyone know? The stuff that was in the pump originally has a sweet smell, but is a milky, light green color. If anyone has a clue to my dilemma, I would appreciate your thoughts. Thanks!!

 

I believe the fluid you are referring to is primarily for lubrication and the flow of the water through the unit provides cooling. As I recall, the instructions with my pressure washer recommend not running it for a considerable lenght of time without "squeezing the trigger." Perhaps that's recommended to extend the life of the seals.

I'd consider the $5 a great deal on the motor and frame and rebuild the pump or better yet bolt a new pump to it. Several compatibility variables regarding bolt patterns, shaft diameter and horsepower requirements are described by vendors on eBay such as the following (not an endorsement by any means):

http://cgi.ebay.com/ws/eBayISAPI.dll...194373737&rd=1

If you go that route, match the pump that offers the highest psi and gpm that requires at least your engine's horsepower. Still a better deal than buying a whole new unit.

/ hates wasting a good motor