pump problems

My general 2021 pumps are only putting put 2200 psi but they will unload at 3200 psi. Ive put in new check valves, new packings and new unloaders still the same.Its not the nozzles their new. its got me stumped anyone got any ideas. the funny thing is i noticed both of them doing it at the same time.

What is your water supply like? plugged filters? How about the valves? are the orings in good shape?

Scott Stone

You've got 2 machines, both with 2021's? Do you draw from the same source water with both? Were they running simultaneously? What size new nozzles are in them?

Yes i pull from the same tank through a 2 inch line down to 3/4 to the pumps. My filters seem to be fine. I replaced check valves with new ones and new orings. I use #6 nozzles. no they were not running at the same time. When i noticed it with my goto machine i shut it down and replaced the check valves because it had ate one of the orings.put some in, still the same thing. So i switched over to my backup machine and same thing. since then i have put on new unloaders new packings new check valves still no change.

I had that happen recently when I was recovering water. Pressure dropped to 1700 PSI and I even repacked one of my pumps. (same deal, two machines on the same trailer) When I started using clear water again, pressure came right back. Still has me scratching my head..

Anybody got any other suggestions, still havent figured it out.

No obstructions in the tank?

Russ no obstructions in the tank. I found out my belts are slipping, tightened them up still slipping guess its time for new belts.

Try a NEW tip. When it Unloads at a higher PSI than it actually puts out this is usually a worn or wrong size Spray Tip. Sometimes this is an indication of scale or soap build-up in the Coils. The way you can find out is to put a gauge on both sides of the coil then compare the readings on both sides. There will normally be a small difference between them because of the coil length (100 to 200 PSI)but a large difference in the indicator. If the Coils are Pluged you have to Descale them with Muratic Acid. NEVER RUN ACID THRU YOUR PUMP>use a diaphram pimp like a Sureflow.