Another Pump Problem

[Johnny]

Ran my Cat 3CP1120 dry for a few minutes last week. Water supply was shut off.

Unloader valve now chatters at about 600+ PSI and the gage needle oscillates.

Works fine for now, but don't want to break down in the middle of a job.

Rebuild pump? Unloader valve? Self-correcting? Best place to get parts?

Thanks!

 

[Jim Martin]

take your quick connect off you solution line and turn it on and see if you can burp it........if the un- loader it chattering .that tells me you might just have a air pocket.....try this first.. is the pump leaking any where ??

 

[Guest]

Check to see if all the allen head screws are tight on the unloader. Do what Jim said hook a quick connect to the machine and flow water for about 10 minutes should get out any trapped air.

 

[Johnny]

I have a bleeder valve upstream of the quick connect with a hose to mix chems in jugs. I ran it for about 30 seconds into the vac hose and have done a couple jobs since. Will try your siggestion and run it for about ten minutes and check the allen screws. Thanks.

 

[Larry Cobb]

John;

The degree of damage depends on the type of plunger Seals you have in the Cat pump.

If they are the Teflon variety (more expensive), the few minutes of dry run will not damage them. They should allow up to 30 minutes of dry run (from our testing).

If they are the standard variety (less expensive), then they most likely suffered some heat damage from the dry run.

The pulsation is usually from cylinders that are not pumping the normal amount of water.

Larry Cobb

 

[Guest]

John one more thing . Check the valves some trash may have gotten in when ran dry. sometimes there is a lititle crap in them. pull them out and inspect them.