FF01U1Q203192 Had to replace a main relief valve on this machine this week. I am a little unsure the adjustment. I understand the high side relief, but the low side relief is a bit unclear in the tech manual. Perhaps I just got tired of flipping through chapters (never been a fan of how Hitachi manuals are set up in the first place) I know how to adjust both high and low on the relief valve, I just don't know the values or steps for the low side. Just to double check with everybody this is how the high side is done: Plumb a gauge into the pump output pressure port (doesn't matter pump one or two) Operate the function with the highest relief setting and hold against relief (so boom up. Book says (iirc) 4850 psi and 5350 with power boost) Adjust lower section of relief valve to spec. Book says a quarter turn is 1030 psi, half turn is 2060 psi. I get that. Let me know if I don't. I can't seem to find how to do the low side
I deleted my original post. Ill try and find the Deere 200DLC procedure, maybe easier to follow.
Check your messsages
Indeed, Hitachi's shop manual is a bit complicated to understand!! It's simply that adjusting the pressure on the high side will cause the pressure on the low side to change as well. Therefore: when adjusting the pressure on the low side, you just need to adjust it and you're done. If you need to adjust the pressure on the high side, you must also adjust the pressure on the low side. Note that: ZX200-3 has an "Auto-Power Lift Control. When operating boom raise with pump 1 delivery pressure in high, MC drives solenoid valve unit (SG) according to the signals from pressure sensor (boom raise) and pump 1 delivery pressure sensor, and increases relief pressure of the main relief valve in control valve".