Pressure Washer Piston Pump Trouble

[Don Orr]

I am looking to the extensive brain trust on this site for some help. I have a small pressure washer with a common Annovi Reverberi piston pump that stopped working. I bought a replacement pump and that works fine. I thought it might be fun to rebuild the old one and have a backup. I watched a ton of videos including the 1 from the manufacturer. I got the replacement/rebuild parts (valves & seals), took the old pump apart, cleaned it out, and installed the new parts. I can't get water (or air) to flow through the pump as it should. I have not replaced the unloader valve yet as the existing 1 seems fine. Any thoughts or ideas ?

[Bill Dufour]

I think it has to be the valves. Even if they leak the pump will move some water at a low pressure. Maybe a valve is backwards? check the inlet screen.
Mine will squirt water as long as the garden hose is on and the trigger is pulled even when not plugged in.
Bill D

[Ronald Blue]

When you say as it should what are you saying? It has a small flow or it has no flow? What was it doing when you replaced it? A stuck unloader would certainly keep you from having anything more than supply line pressure.

[Don Orr]

All valves are properly in place. Nothing will go through the pump at all. This is what happened when it failed. No supply pressure at all. Can't even blow air through it. Inlet screen is clean. I'm stumped.

[Ronald Blue]

Which pump is it? I'd like to look a parts schematic.

[Don Orr]

It's and Annovo Reverberi Plunger Pump model # RMW2.2G24 (also SRMW series)

Should be this manual. https://www.arnorthamerica.com/Pages...mw-om-1006.pdf

Thanks for any input.

I think I will get a new unloader valve and see what happens. That seems to be a common solution from what I can find in several sources.

[Ronald Blue]

I'm sure you explored this already but there isn't any obstructions on the inlet screen/tube is there? I've had very low flow because the supply hose had debris in it that collected at the screen. Cleared it and all was well. Just a thought.

[Ole Anderson]

I've replaced the case seals (same pump) to stop an oil leak and I've fixed, then ultimately replaced the unloader. No help on your problem, sorry. But when I replaced the unloader (prior the Honda engine would stop dead if the nozzle wasn't squirting), now even with the spring compressed fully, I am not getting the pressure I used to and the engine hardly slows down when I release the trigger.