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  1. J

    Hitachi EX120-2 won't start!

    It's all good! I appreciate your willingness to help.
  2. J

    Hitachi EX120-2 won't start!

    Ok, here are a couple of pics of the pump. The stop motor cable is not in the pictures, I had already removed it before taking them.
  3. J

    Hitachi EX120-2 won't start!

    After further inspection... the stop motor has some serious issues! It must have gotten really hot at some point, I'm thinking before I owned the machine. That problem where it intermittently wouldn't shut the engine down, well that's probably because one of the magnets inside the motor casing...
  4. J

    Hitachi EX120-2 won't start!

    It runs now! I loosened the jam nut on the stop motor cable and pulled it out of the bracket. As I pulled it out, the spring on the stop lever pulled the lever forward about half an inch into the run position. Gave it some glow plug action, turned the key and it fired right up. I have since...
  5. J

    Hitachi EX120-2 won't start!

    I replaced the line from the tank to the water separator and just had all the hard lines off that go from the separator to the supply pump and then from the supply pump top the fuel filter while I was looking for that screen. Put it all back together and primed up good with the hand pump. No...
  6. J

    Hitachi EX120-2 won't start!

    Ok, I got the banjo bolt off at the bottom of the supply pump. There is no filter screen to be found, just an empty banjo bolt. Looked with a mirror, doesn't look like the filter is stuck up inside the supply pump. I also took off the line exiting the supply pump that goes to the fuel filter...
  7. J

    Hitachi EX120-2 won't start!

    I had my brother spray brake clean into the intake and it did want to run on that. I will not run afterward on its own. There is no positive air shutoff. It has glow plugs, temperature was around 0 deg C. I usually use the glow plugs when it gets around freezing. When I do forget to use the...
  8. J

    Hitachi EX120-2 won't start!

    Hi all, My 120 won't start and it has what I think is a fuel issue. I have done a bunch of things to diagnose it but to no avail. Hoping someone can show me what's staring me in the face. - Ran fine the last time I used it, didn't notice anything unusual. - Sat for about two weeks, came back...
  9. J

    2004 Case 60XT loader jerking downward

    Today I pulled out the "Lower Counterbalance Valve". I found a smushed o-ring on the outside and when I pulled it apart there was only half a backup ring left on the check valve. From what I understand this valve controls the oil flow coming back from the lift cylinders and helps lower the...
  10. J

    2004 Case 60XT loader jerking downward

    Hi Everyone, I'm looking for some wisdom with the Case skid steers. I have a 2004 60XT with the bi-directional self leveling option. I recently bought the machine and did some maintenance along with a paint job and new decals to freshen it up. The problem happens when I go to lower the loader...
  11. J

    EX120-2 system base pressure too low

    So... just wanted to let you guys know that I have a youtube channel now. I sent a message to the moderators asking if I could announce it hear but did not get a reply so hopefully its ok. If you are interested you can go to youtube and search " EducatedGuessing Excavator Crane ". There are two...
  12. J

    Dr. ZX communication problem with John Deere 490e (Hitachi 120 equivalent)

    Hey Joel, unfortunately I am in the same situation as you, although mine did work for a while. When I first got it, it would not connect with the plugged clicked in correctly. So I flipped it over and plugged it in (without de-pinning the connector like you did) and it connected. I went through...
  13. J

    Boom down randomly becomes weak when warmed up - John Deere 490e excavator

    Sorry mg2361, a small correction if I may... 24 deg is the max pump angle. At idle with the control levers in neutral the pump angle should be 3-5 deg.
  14. J

    EX120-2 system base pressure too low

    I replaced the entire main control valve (distributor). The control valve actually splits into 2 pieces after removing the 4 big allen headed bolts. One side has bucket, boom, arm and auxiliary spools and the other has the main relief/unloading valve, swing and both travel spools. I think I...
  15. J

    EX120-2 system base pressure too low

    Yes, I put air pressure into the control valve (distributor) through the oil inlet to check for leaks. With the control levers in neutral the oil flow is blocked by the main spools and the unloading valve. The unloading valve is supposed to bypass oil when 284 psi is reached. Mine was only...
  16. J

    Boom down randomly becomes weak when warmed up - John Deere 490e excavator

    Yours would be equivalent to a -2 Hitachi. John Deere has a split at 25000. 24999 and down is -2, 25000 and up is -3. I would try clearing the codes and running the machine again until the problem appears. Then force it to do the problem a few times so that it will store a code. Any of those...
  17. J

    Hitachi EX100-2

    Sounds like it could be a problem with the load sensing shuttle valves. Since your machine has the manual conversion it is unlikely to be the proportional solenoids that control the variable pressure compensated valves. The computer controls these for combined operation of functions. The...
  18. J

    EX120-2 system base pressure too low

    We have success! I can now reach 5000 psi with every function in P mode and the hydraulic oil up to temperature (50C). I unplugged the pump control solenoids and let it fall to maximum angle (24 deg). I then back probed the electrical connector for the angle sensor (one probe on signal and...
  19. J

    EX120-2 system base pressure too low

    I set the angle sensor according to the instructions in the manual. It says to set the angle sensor to read 4.40V +- 0.03V when the pump is at 24 deg. - Is there a different voltage that you have found to work better? I tried a quick test today. I unplugged the pump angle control solenoids and...
  20. J

    EX120-2 system base pressure too low

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