How JustAnswer Works:

  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site.
    Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.

Ask Dan Your Own Question

Dan
Dan, Field Technician
Category: Construction and Road Equipment
Satisfied Customers: 4560
Experience:  17+ yrs. shop and field experience with all major brands of heavy equipment, trucks and farm equipment - 1995 WyoTech graduate.
65405794
Type Your Construction and Road Equipment Question Here...
Dan is online now

1.) I had a problem regarding the LS120 Mitsubishi Excavator

Customer Question

1.) I had a problem regarding the LS120 Mitsubishi Excavator where I had replaced the main pump and also the small pump for the hydraulic control but the travel motor works soooo slowly and it doesn't work normally and what shall I do to correct the problem?
2. Also the same with the same model LS120 Mitsubishi Excavator I had also replaced the Main hydraulic Pump and the small pump for the hydraulic control but the unit when at its operation the engine even at high idle will shut down and what's the problem that we can solve it very soon.
Submitted: 10 months ago.
Category: Construction and Road Equipment
Expert:  Shantal-Mod replied 10 months ago.
Hello,
I'm Shantal and I'm a moderator for this topic.
I've been working hard to find a Professional to assist you with your question, but sometimes finding the right Professional can take a little longer than expected.
I was checking to see if you had already found your answer or if you still need assistance from one of the Professionals.
Please let me know if you wish to continue waiting or if you would like for us to close your question?
Thank you,
Shantal
Expert:  Shantal-Mod replied 10 months ago.
Hello,
I apologize as we have not yet been able to find a Professional to assist you. Do you wish for me to continue to search for someone to assist you or would you like for us to close your question at this time?
Thank you for your patience,
Shantal
Expert:  Dan replied 10 months ago.
Hi Mario, Be sure the system is completely flushed and there is no metal/debris in the system or filter. 9 times out of ten slow travel is related to rotary manifold seals bypassing pressure internally. Reseal your rotary manifold.
Dan, Field Technician
Satisfied Customers: 4560
Experience: 17+ yrs. shop and field experience with all major brands of heavy equipment, trucks and farm equipment - 1995 WyoTech graduate.
Dan and other Construction and Road Equipment Specialists are ready to help you
Expert:  Dan replied 10 months ago.
Hi Mario did you reseal the rotary manifold? If so and there is still trouble your drive motor will likely be faulty. Check for excessive case drain pressure by removing the case drain line, running a hose into a bucket, pin the track and sprocket to prevent travel, engage travel and if oil comes out under high pressure the drive is bad. It should be low volume of oil. Compare both sides
Customer: replied 10 months ago.
Yes that's what I am thinking of to inspect the LH/RH drive motors but I am also in doubt why both travel motors was defective immediately and is it it possible that there's a problem in the control valve? And the reason I asked you because I believed that 2 heads are better than one and being a mechanical engineer and also service manager to an American and Japanese products it's also my thinking that I can solve it with more suggestion rather than opening right way the system from the unit. Thanks
Expert:  Dan replied 10 months ago.
Hi Mario, As mentioned in my first response rotary manifold seals are the number one cause of travel problems and commonly get misdiagnosed for a failed travel motor. Resealing the manifold is a part of troubleshooting. Also check the relief valve cartridges on the main control valve and check for excessive case drain pressure in the drive motors.

What Customers are Saying:

 
 
 
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
< Previous | Next >
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
  • Thank you for all your help. It is nice to know that this service is here for people like myself, who need answers fast and are not sure who to consult. GP
  • I Couldn't be more satisfied! This is the site I will always come to when I need a second opinion. Justin
  • Just let me say that this encounter has been entirely professional and most helpful. I liked that I could ask additional questions and get answered in a very short turn around. Esther
  • Wonderful service, prompt, efficient, and accurate. Couldn't have asked for more. I cannot thank you enough for your help. Mary C.
  • This expert is wonderful. They truly know what they are talking about, and they actually care about you. They really helped put my nerves at ease. Thank you so much!!!! Alex
 
 
 

Meet The Experts:

 
 
 
  • cumminsdr

    cumminsdr

    Mechanic

    Satisfied Customers:

    14
    Cummins field tech
< Previous | Next >
  • http://ww2.justanswer.com/uploads/cumminsdr/2010-7-20_204410_ja.jpg cumminsdr's Avatar

    cumminsdr

    Mechanic

    Satisfied Customers:

    14
    Cummins field tech
  • http://ww2.justanswer.com/uploads/bobbylong/2008-06-12_203111_bobby_mini.jpg Bobby Long's Avatar

    Bobby Long

    Technician

    Satisfied Customers:

    207
    16 Years experience in Bobcat, And International tractor repair
  • http://ww2.justanswer.com/uploads/dusgrant/2010-11-17_001335_06-06-08_1810.jpg DDG's Avatar

    DDG

    Service Coordinator

    Satisfied Customers:

    104
    2 years Truck shop experience, 12 years of Bobcat Compact Equipment experience
  • http://ww2.justanswer.com/uploads/ErikBowers/2009-09-03_140413_Picture_147.jpg Erik Bowers's Avatar

    Erik Bowers

    Owner, operator, mechanic

    Satisfied Customers:

    97
    small engine expert, hydraulic & robotic expert, heavy equip mechanic
  • http://ww2.justanswer.com/uploads/Gtorseth/2010-06-26_230010_n100000021244814_7742.jpg Greg Torseth's Avatar

    Greg Torseth

    Mechanic

    Satisfied Customers:

    82
    Over 15 years of Agriculture and Construction Equipment repair expierence . Factory Trained
  • http://ww2.justanswer.com/uploads/eteck460/2010-1-14_65631_893.jpg Keith's Avatar

    Keith

    Technician

    Satisfied Customers:

    13
    ASE master diesel mechanic 24 years exp.on heavy trucks and trailers