Pump Pulsation

Michael T

New Member
Wiz or anyone,
Ive got a Rk-21 and the problem Im having is pump pulsation. Not a lot but enough to be annoying. The unit has a general 2021 belt drive. 3000/5.5. If you put your foot on the hose while under pressure you feel some pulsation. Ive replaced packings and check valves and orings and still get pulsation. I have other machines with this same pump and they dont do this. It does it at all psi settings, less noticeable at 3000psi though. Any tips, hints or tricks? I cant figure it out. Im creating a bald spot on this one so please help before I run out of hair.

Michael T


Moderator / Sponsor
Troubleshooting General Pumps

Probably the first thing I would do is force feed the
inlet to the pump,and look for leaks.
<i>(If it is leaking water from under pump, it is probably
sucking air also.)</I>

Here is some pump trouble shooting stuff from General Pump:

On Line Troubleshooting Guide

Scroll to the bottom of the linked page for troubleshooting guide.

Hope this helps! :)


New Member
I had that same sort of thing happen to me. It ended up being an air leak. Easy fix, replaced an o ring on the pump. Happened again sometime later, and it was a damn bumble bee in the water hose at the filter of the pump. Must have tried to find a new home.



This problem can be caused by a number of things.
Air could be getting into the system some how. Check all of your clamps. Check your soap valve make sure it is closed or the hose is in water if not using soap. Check all of the hoses for worn spots and pin holes. Force feed the pump to find any leaks. Check all of your plumbing and tighten any loose fittings. Something is stuck in the system. Check all 6 valves aswell as the O-Rings under them. Check the filter screen for something restricting the flow. Check the hoses for kinks. Check the Ceramic pistons for hairline cracks. Check the unloader for something stuck inside. Call me if you need more suggestions.

Michael T

New Member
pump pulsation fixed

Fixed the problem the other day . Thought I would send a reply and thank everyone for the imput. :D A BIG THANKS. :D
The problem was an air leak in the filter. I installed a filter between float tank and pump. there was a leak at one of the fittings. Took them all apart and put new teflon tape on all threads and hose barbs. Problem solved, no air leak, no vibration.

Best Regards,

Michael T

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