1. Thank you for visiting HeavyEquipmentForums.com! Our objective is to provide industry professionals a place to gather to exchange questions, answers and ideas. We welcome you to register using the "Register" icon at the top of the page. We'd appreciate any help you can offer in spreading the word of our new site. The more members that join, the bigger resource for all to enjoy. Thank you!
  2. ALL NEW MEMBERS READ THIS FIRST!! Thank you for joining Heavy Equipment Forums! If you are new to forums we communicate with "Threads", please search our threads to see if your topic may have already been answered and if not then click "Post New Thread" in the appropriate forum. This will allow all of our members to see your question and give you the best chance to be answered. After you've made a number of posts you will graduate to Full Member status where you'll see a few more privileges. Following these guidelines will help make this the best resource for heavy equipment on the net. Thanks for joining us and I hope you enjoy your stay!!

Hitachi 120-2 questions and anwsers

Discussion in 'Excavators' started by SoutheastSavage, Sep 27, 2020.

  1. Garter

    Garter Member

    Joined:
    Sep 7, 2020
    Messages:
    13
    Location:
    Ireland
    No problem, as I said if you need more detailed images just shout.
     
    JDCrow and SoutheastSavage like this.
  2. bdward

    bdward Active Member

    Joined:
    Sep 11, 2014
    Messages:
    28
    Location:
    alaska
    I just got a EX100-3 that may need the conversion kit but I haven't done any of the diagnostics yet. There is NO electrical control of the throttle and to even start it and I need to hold the pump throttle control with a wedge to set the speed. I ALSO HAVE ONE OTHER ISSUE I HAVEN'T HEARD ABOUT IN ANY POST. I don't have any electric control for track speed. It's fixed at slow speed. Is this part of the problem a conversion kit will fix? Your responses are appreciated.
     
  3. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    so With your throttle control, conversion won’t fix. You can check the EC. Motor throttle motor to see if it’s getting power if it is make sure your throttle cable isn’t bound or seized. ?? And if your machine functions fine as far as not bogging when you use hydraulics I wouldn’t do the conversion. If everything works fine except throttle and track speed. I would try to track those issues down. If machine does bog and has other issues. Throw a manual throttle in and get a conversion kit on it
     
  4. bdward

    bdward Active Member

    Joined:
    Sep 11, 2014
    Messages:
    28
    Location:
    alaska
    Thanks for your response. So far by jamming a screw driver between the pump throttle shaft & stop to speed up the engine, I seem to have proper hydraulic operation. Is the conversion kit mainly to replace the computer signals that maintain the proper pump stroke during a load and nothing about the throttle motor control? If so I see your point. I'll check those functions. Fortunately I have the books though their sometimes hard to follow. Need to get on this as it's starting to cool down here in Delta Jct. - Thanks again
     
  5. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    Yeah your right there. I would suggest checking for power at throttle control. If there is power and nothing is working consider buying a new one. I think they are about 150 bucks on eBay. Or Friday parts.
     
  6. EZ Repair

    EZ Repair Member

    Joined:
    Jan 22, 2019
    Messages:
    14
    Location:
    Bacolod, Negros Occidental, Philippines
    Garter likes this.
  7. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    This is the instruction for the conversion kit that I have been able to find. I haven’t installed my conversion yet. But I plan to soon
     

    Attached Files:

  8. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    Haven’t been on in awhile and I just wanted to let everyone know that I did the conversion on my 120 today.
    After conversion I experience no bogging and plenty of power. I haven’t ran it for a long period of time but so far am very pleased. Conversion took about 3-4 hours and was fairly easy to do. Instructions are not great but good enough. I took some pictures of my work today here they are and cheers everyone that helped and gave me info and pictures it helped a lot
     
    Garter, alaskaforby4, mg2361 and 2 others like this.
  9. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
  10. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
  11. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    If anyone needs advice let me know I will be installing a manual throttle tomorrow and will add some pictures of that
     
  12. JDCrow

    JDCrow Well-Known Member

    Joined:
    Sep 25, 2020
    Messages:
    102
    Location:
    Redmond, Or
    Still and option for me. Still dealing with boom up. Thanks for pics. It does look pretty straight forward
     
  13. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    Yeah after running machine a little I noticed that my stick in. Is very slow and sometimes can only do one function at a time can’t boom up at the same time. Thinking about putting more shims in conversion any input ?
     
  14. LACHAU

    LACHAU Senior Member

    Joined:
    Aug 11, 2009
    Messages:
    514
    Location:
    Saigon, Vietnam
    1. "..stick in. Is very slow" If single action, It relate to "DIFFERENTIAL PRESSURE CONTROL" to increase pump flow.
    2. "..can only do one function at a time can’t boom up at the same time". It relate to "PRESSURE COMPENSATION PROPORTIONAL SOLENOID VALVE" or we can say that is "FLOW SHARING PRINCIPLE".
    EX100_EX120-2 Compensation Hydraulic Circuit.png
     
    Last edited: Mar 20, 2021
  15. LACHAU

    LACHAU Senior Member

    Joined:
    Aug 11, 2009
    Messages:
    514
    Location:
    Saigon, Vietnam
  16. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    So I ended up disconnecting my PVC completely which fixed the issue. My machine works as it should. No pvc and no pump electronics. It is working very well have used it for about 4 hours
     
    JDCrow likes this.
  17. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    0FD1B603-907E-4C94-A644-6A22BF01DBA4.jpeg EBE0E9C3-F1CA-4CBF-BF6D-F6323DE388BD.jpeg BEEB81D5-EADB-4F4D-A198-5657C74D174D.jpeg 0FD1B603-907E-4C94-A644-6A22BF01DBA4.jpeg EBE0E9C3-F1CA-4CBF-BF6D-F6323DE388BD.jpeg BEEB81D5-EADB-4F4D-A198-5657C74D174D.jpeg
     

    Attached Files:

  18. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    So I’m thinking about replacing my bucket pin and bushings. I have a thumb so I’m curious on if I need to get a longer pin and how many bushings ? 6 2 on thumb 2 on bucket 2 on boom ?
     
  19. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska
    So anyways I had a machinest look at my machine and is gonna build me a new pin. I have 6 new bushings coming for bucket stick and thumb. I also installed my manual throttle which was very easy to do and works great. Machine continues to work well with the conversion kit. Very happy
     
  20. SoutheastSavage

    SoutheastSavage Well-Known Member

    Joined:
    Sep 27, 2020
    Messages:
    46
    Location:
    Kasaan Alaska