Cat pump

[kwikwash]

coleman self serve 5cp2120 pump running high over 2k but when i pull trigger gun drop back down to 1400psi. Any idea what causing this? Thanks. Im glad i found this website. new at this

 

[MEP001]

Regulator is set too high or is bad. If it's a Paraplate and you can see rust weeping from the holes in the body, it's been bad for months.