CAT 2120 pressure adjustment

[stampedecarwash]

Hello, i run my pumps at 1200psi. One of them is a bit lower like 1100 psi. When i try to adjust it by turning the nut on the bypass/regulator, it will go up a bit like 50 psi but as i keep turning the nut the pressure goes down again. The regulator is brand new not sure why it acts like that. Thanks

 

[MEP001]

It's probably not the regulator. You can check by pinching the bypass hose closed and listening for flow.

You could have a problem with the pump, a bad check valve somewhere, or your tip could be too big.