911! Help w Lost Pressure!


On a job and my washer/pump has lost pressure. All connections are made, 500 gal buffer tank w gravity feed to belt driven washer, started out fine. Removed belt cover, belts are turning fine. Removed valves one by one, blew out and replaced. Out of ideas?!?


Also, it “pulsates” from low pressure to no pressure, which is what was making me think it wasn’t getting water, but I don’t think that’s it.


Hook hose up to it from a spigot and run it for a minute. Needs primed or something blocking it.

Start there, had the same problem when I first used my belt drive a few weeks ago


Air leak from buffer to washer?
trash in inlet filters
unloader do fail over time
Im guessing you mean you checked the pumps check valves. But they can still be bad if they are not seating properly. To tell if they are bad you would have to suck on them not blow. They should not let air through when sucking them if they are seating properly


Sounds like a failed check valve. Or air in inlet The best way to check them is to put new ones in.


I usually idle mine super low and squeeze the trigger until it primes. Then ramp the motor rpm up to operating speed.


That did it! Sorry for the delayed response, (just got home from the job) I really appreciate it! Guess I may have to get a pump to feed the washer? Did you go back to gravity feed after switching over?

Thanks again friend.


Thanks everyone for your responses. Got some good pointers from this thread I’m going to log for later.


Went back to gravity feed 5 minutes later and no issues since.


Meant to update this sooner . . . so there are different threads for hoses whether they are industrial hoses or garden hoses. I took my trialer to a local pressure washing mechanic, and he discovered two sources of my cavitation of my pump. 1. the hose that I had home made with barbs/threaded ends/clamps I had used NPT thread to try to connect my water line to the intake for the pump. Obviously these did not marry up, and caused a problem. He replaced with the correct GH threaded end and solved that one. 2. the second source was where I went from 3" pvc to a 1" wye, I had threaded ends on each of these (GH), but again, had the NPT on my hose. I applied a converter to this connection, and now it is drawing like it should, and producing the pressure I am accustomed to. Thanks everyone for the pointers - Just a word to the wise that most on here probably know, make sure your hose connection are GH, or if NPT make sure they are consistent and converted where necessary.