Unloader Valve? Or Pump?

I do small pressure wash jobs part time to supplement my retirement income. I wouldn’t call myself a highly experience expert, but I’m no dummy either and I know how to diagnose and fix all the common problems.

I have Troy-Bilt XP washer, model 020489, with Honda GCV-190 engine, Annovi Reverberi pump 3000 PSI 2.7 GPM. It has probably a couple of thousand hours on it, but I keep it clean, change the oil, and do all the maintenance. I treat it like the money-making piece of business equipment / expensive tool that it is.

On a recent job, towards the end of the day, I lost pressure. The symptoms indicated a stuck unloader valve, and upon inspection, it was indeed stuck. No amount of fiddling with it and carb cleaner, brake cleaner, and PB blaster would unstick it. Had to quit for the day. I ordered a new unloader valve.

In the meantime, I left the old valve soaking in PB blaster. After 2 days of soaking, it came unstuck. Not trusting it, I installed the new valve on my washer when it arrived.

When I fired up the washer, the engine is running all-out, several hundred RPM above normal, and I still no pressure (beyond what you get from the faucet). OK, so I figured the new valve needed adjusting. Never had the need to adjust one before, the factory adjustment on the old one worked fine. After much fiddling and adjusting following many different people’s instructions, I was unable to solve the problem. (Engine still running fast, poor pressure). I reinstalled the old valve which still had the factory adjustment that had been working great. And I STILL have the same problem.

So whadda ya think? Is this an unloader problem, or has the pump failed? Maybe a broken or stuck leaf valve in the pump?

disconnect the pressure hose and see how the pressure is coming out straight from the pump. Good chance your trigger gun could be the issue