I have a EX120-5 with a auxiliary circuit for a thumb, hammer, etc. I need to lower the operating pressure for this circuit to 2500 psi. I've done this on a Ex120-2 machine and it's straightforward. The control valve on the -5 models is different. I thought I located the relief adjuster on the valve just above the return line coming into the valve. It has the 17mm cap with a screwdriver slot underneath. The cap was painted red so I assumed it was correct. I've adjusted the screw both in & out (up to 2 full turns) and it makes no difference in the line pressure. The line pressure is 4500 psi, same as pump pressure. Can anybody help me find the right location to adjust this pressure. I need the operating pressure lowered to 2500 psi both for motors and the thumb. I've looked in the service manual & can't find any reference. I'd appreciate your help.
According to the circuit diagram the aux circuit doesn't have relief valves in the control valve. They may be fitted external. Best thing to to is follow both aux lines coming from the control valve and see where they go. There'll probably be an external block with relief valves in that