Pressure Washer - Low Pressure

[GregJ]

Just one more thing to consider..... I have had a problem with my pressure washer unloader valve sticking. If it sticks on the relief side, you will have no pressure. If it sticks on the pressure side, it won't have any relief when you release the trigger. I finally figured out how to disassemble it and clean it up. Depending on your water quality, you can get a significant buildup in these pumps.

Just a thought...

Greg

 

[jgbanshee]

If the relief valve is stuck open, wont the water pour out of it?

 

[GregJ]

The unloader valve is internal. It's not the relief valve that drops water out of the pump when it gets warm. If you listen to the pump as it works, when you pull the trigger, the engine goes under load and the pressure builds. When you release the trigger, you can hear the load released on the engine. The unloader valve on mine is a simple little plastic piston with an o-ring that moves under pressure and diverts the flow of the water internally to relieve pressure on the pump when water is not flowing......

Did that make sense /forums/images/graemlins/crazy.gif .... I haven't finished my second cup of coffee yet....

BTW, there was a thread here some time ago with the same complaint. I shared this with the poster and it turned out to be his problem as well. He had no pressure and his unloader valve was stuck. I think other people mentioned they had the same problem. I took the time to figure out how to remove and clean mine, because I figured it could be a regular maintenance item and I don't want to have to take it in for repair every time I have a calcium build up.

Greg

 

[jgbanshee]

I dont remember seeing a little plastic piston and o-ring when I had it apart. Where is it internally?

 

[GregJ]

I don't have the same pressure washer, so I can't tell you exactly what to look for. You should be able to go to the manufacturers website and get a parts schematic that will have the unloader assembly labeled. Mine was buried pretty deep inside the pump. It took me awhile before I finally figured out how to get to it. I'm sure that some are easier to get to than others.

Hope this helps,
Greg

 

[GregJ]

I just did a quick google and found a great website that has unloader and pump breakdowns for Devilbiss pumps. Take a look at Parts Breakdowns

Hope this helps,
Greg

 

[jgbanshee]

Ok, I found the unloader. Parts Breakdown of my pump. The unloader is number 27 according to the list. I thought that you said it was internal.

 

[GregJ]

Mine is internal. Looks like yours will be really easy to get to.

Greg

 

[frank_f15]

NOT SURE OF THE TYPE OF WAND AN NOZEL YOU HAVE, but when i had that problem i took it apart and found nothing wrong, BUT i had a spare wand and nozel and that worked fine, so i determined it was the nozel ,took it apart agin and found i small orffice i did not see 1st time, cleaned that out and all was fine. just throwing it out there.

 

[GregJ]

Well.... Any luck? Just curious to see if it worked.

Greg