CAT 340 Vibration in Bay Gun

[MDrost1]

Folks,

I may be nitpicking here, but my CAT 340 runs smooth. Although, intermittently during a HP cycle, I receive a little vibration/pulsation. It lasts a few seconds, then goes a way, comes back few seconds later. I replaced the valve kit. The head was rebuilt about a year ago. I rebuilt the low pressure manifold, thought it might be taking in air some where. None of the things seem to remedy the situation.

Weep check?
Drawing air from somewhere else(fitting etc).
Something else?

Advice is much appreciated!

Thanks.

 

[Randy]

It sounds to me like you've got an leak somewhere in the system, they are always a bit$h to find.

 

[chaz]

Or maybe some debris in the spray tip?

 

[BBE]

I agree a small leak somewhere. It's causing it to suck air.

 

[mac]

Look at this older post. Might be the answer: http://www.autocareforum.com/showthread.php?14766-Bays-cavitating-only-when-all-bays-are-full

 

[MDrost1]

Still working it out. First thing in the morning it stutters pretty heavy, then smooths out. However, the little vibrations are still there. Any tips as to how to find an air leak?

 

[Jim L.]

Is there a check valve in the water supply line to the pump? I've had a broken one of these try to starve my pump.

Also try plugging the soap/wax port on the side of the pump and see if the problem goes away. It will narrow down where to look.

 

[MDrost1]

Well,

To me it seemed as though it was grabbing air from a fitting somewhere. I bit the bullet and took it apart, put a different head on the pump and re-plumbed the pump. All good...Thanks, guys.