Cavitating Pump

[Mike V]

Hydrotek Skid - K7 unloader ..... great pressure when gun is squeezed, when trigger is released, the pump pulses...the little button on the bottom of the unloader goes in and out as it pulese. This is a brand new Unloader.

I have checked every possible place for an air leak and coud not find any, even bypassed the filter to see if there was a leak there.

What else could be causing this? Thanks!

 

[tomtucson]

Does it bypass to a tank? I think the k7's need a small enough bypass hose to provide backpressure or they will pulse.

 

[Mike V]

3 of of my 4 Hydroteks do bypass back to the tank, this one bypasses back into the pump inlet with a T.

Would that make a difference?

 

[tomtucson]

That's all I got. Bypass to the tank is better if you can.

 

[mike barrett]

K7 unloaders come with different sized by pass orifices, the number is stamped on it.
If it's a 5.5 gpm pump if I remember right it takes a #2, look on your old unloader to see if the numbers are the same.

 

[Russ Johnson]

Actually, the K7-2 works better with a #1 bypass orifice. See what the old unloader has in it, and switch them out if it's smaller.

 

[Mike V]

I ran the bypass to the tank instead of the pump.....cavitating gone. Thanks guys!