[jclemmojoe]

I have an Excel pressure washer with a DeVilbiss pump that was working perfectly when I winterized it. When I started it recently the pump pressurizes without the trigger being pulled and unloads when you pull the trigger, exactly opposite the way it was designed to operate. Anyone have any idea where to start looking for the problem?

Thanks, Joe

 

[Thurman]

Worked on many pressure washers, but not sure I understand what you are describing here. "The pump pressurizes without the trigger being pulled". The pump should build up pressure until it reaches the relief pressure point--then the by-pass valve will open to re-circulate water through the pump keeping a constant pressure on the system. When the wand handle is pushed/squeezed/opened, the pressure within the pump will drop, causing the by-pass valve to close and allow all water/pressure to go to the wand. Now--what part of this is going wrong with your unit?

 

[jclemmojoe]

Sorry I wasn't able to explain my situation better. The pump doesn't seem to be in by-pass when the trigger is closed. The hose is fully pressurized and becomes very rigid until I pull the trigger. It then seems to go into by-pass as all that comes out of the wand is water flow at hose pressure. As I recall when it was operating properly it would function the exact opposite. Pressure hose would not pressurize until the trigger was pulled/opened. Could the un-loader be stuck? If so why wouldn't I get pressure when I pull the trigger?

Thanks

 

[jarheadoo7]

im still confused..

with the pump running..when you have the trigger depressed the pressure drops to the equivalent of a garden hose..but when you let go of the trigger the pump pressurizes the hose?

when you initially pull the trigger do you get a short blast of pressure then go to garden hose pressure?

 

[jclemmojoe]

Yes! If I do get a surge it is almost undetectable.

Thanks