Hi I have a trouble Hitachi ZX200-5, all actuator speeds are slow, no fault codes, when I connect Dr.ZX and display Pump 1 Delivery pressure, Pump 1 flow control pressure, pump 2 delivery pressure and pump 2 flow control pressure the delivery pressure on both pumps is 31Mpa, but the flow control pressure on both pumps is only 2.6 Mpa when relieving any function, the reference value on technical manual is 4Mpa. I appreciate any help.
Check your pilot pressure. I've had issues with pilot filter plugging and or the relief that's located in the filter housing. If your pilot pressur is low, your spools will never fully open.
Hi Deeretctech thanks for your help, i´ve checked the pilot pressure on pilot filter port, 520psi at idle and 600 psi at fast idle, i changed 1 pump control pressure sensor but the pressure on Dr ZX is the same, i dont know where it comes from this pressure, or where this pressure is controlled. I apreciate any comment.
600 psi is about 4.1 MPa which is ok. You have 2 pump control valves on the MCV. The 5 spool section has one at the front L/H side and the 4 spool section has one at the rear R/H side. Its these that send the pilot pressure to the pump regulators. Its unlikely but not impossible that both have failed at the same time. I'd start by stripping these and checking.
Hi I am having the same issue with a zx200-5...slow on all functions,machine has only 600hrs on it..got readings up on the dash but everything seems to be reading correct values..did you get to the bottom of your this issue kobo40
I've run into older machines that had screened fittings at the pilot inlets of at each pilot control valve. The screens will pick up contaminants and start to cut off the pilot flow to the valves. Not sure if your machine has these but it may be worth looking into.
Hello, I'm having issues with my zx200-5g excavator,slow on the functions especially for driving a montabert hammer.Has anybody got any info on the pilot pressure for these type of machines.