Long time lurker here, tons of great info while i resurrected an old ex120-2. I've finally got the PVC and EC Happy. The machine has the power and speed id expect. The last nagging issue that I'm trying to solve is the curl and stick movement are jittery/chattering, sometimes to the point it'll shake the whole machine. I mostly notice it when there is no load(free moving in the air) and not doing combined movement(If I'm operating stick and boom at the same time it doesn't seem to do it). No Hydraulic Leaks, I've run it for several hours and held all the functions over relief thinking maybe some stubborn air but there has been no noticeable improvement. No aeration noticeable in tank. No faults in PVC or EC. Fluid level is good, all new filters. Suction screen is clean. Tank has positive pressure in it after running as expected. Boom, swing and tracking all seem smooth. It appears this machine has an EX120-3 valve block as well for what its worth. I have a pressure guage set and MpDR but am a bit lost where to look for this issue. main pressure and pilot pressure are to spec, both with a gauge set and in mpDr. DP dances like crazy while operating controls, but i believe thats how its supposed to be?
Hey Matt, Sorry I dont have an answer for you on your problems but I'll keep thinking about it. What caught my eye is you say you "finally" got the PVC and EC happy. I am having issues with mine! I am trying aftermarket without success. Can I ask what you did? Thanks
Nothing ground breaking, replaced all the sensors, fixed a bunch of wires. Getting mpDR was a turning point and made it way easier/faster to pin point where the problems were. Highly recommend it if you dont have it. I regret not getting it early on in the process.
Yes I just got one too and feel the same way. Ive done solenoids, wire harness and aftermarket PVC and EC. Pump angle goes to full after 15 second of running. Are your PVC and EC genuine Hitachi or aftermarket.
In mpDr you can view what the computer is commanding the pump to do. Have you checked voltage at the solenoids? The Power to the solenoids was one of the circuits I had to repair it was touchy and would come and go. What faults are you getting? As far as i know i have genuine modules. I never replaced them.
With help from a few on here I have done extensive testing. It all points back to the PVC and possibly the EC. Now comes the decision, what do I do next? Im hoping to find someone with an aftermarket PVC and the part number the serial number of the machine.