Hey there fellas I have a 04 hitatchi 160 and believe the aux hyd relief for thumb is giving me trouble originally one day out of no where it had no squeeze pressure , so I switched hyd ram lines to check ram has great squeeze but now weak opening, so in my mind it's that hyd circuit and not the ram , can anyone give me insight to location of the aux hyd reliefs assuming that's the issue Thxs in advance
Welcome to HEF blackcat . Is the thumb open and close speed normal ? The auxiliary circuit relief valves are located in the main control valve directly above and below the auxiliary plumbing tube/ hose 4 bolt flange connections.
Thxs for the welcome, the one circuit is slow depending on hose orientation, you can almost hear fluid bypassing sound when pushing button in the slow or weak direction, I'll chase some lines in am once it's cooled off , assuming the lines and reliefs will be on hyd tank side of machine? Thxs forthe quick reply
Pic attached showing the layout of the main hydraulic control valve functions. .
Hey quick up date followed lines confirmed with diagram swapped reliefs issue switched back to weak squeeze removed relief disassembled relief found a small piece of something don't believe it was metallic , cleaned re assembled ran for 8 hrs issue free thanks for the help!
Using the monitor diagnostics, confirm the thumb cylinder barrel end circuit relief is set relatively low ,approx 14-16 mpa (2000-2300 psi).
Mine has a pretty basic monitor set up I'm un aware if it can do that , has heat and fuel in a sweep type gauge then one digital that can be switched from hours , job clock and something else.
Press and hold the set button then key on or start. After bulb check release the button. Then use the select button to scroll. Hi lite Pump 2 delivery pressure. At about half throttle , extend the thumb cylinder to the end and record the pressure. ****edited, Pump 2 ***