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Komatsu PC50MR-2 Motor stalling.

Discussion in 'Excavators' started by pfpm, Jul 4, 2012.

  1. pfpm

    pfpm Member

    Joined:
    Nov 4, 2011
    Messages:
    24
    Location:
    Australia
    Some time ago I had PC50MR-2 which had a motor stalling problem which was intermittent but more frequent after a few hours operation. After much testing and investigation I determined that the servo piston was Hanging up and not allowing the pump to compensate, Hence the stalling motor. I found abnormal wear in the swash-plate servo piston bore. We replaced the pump and had no more problems.

    This afternoon I am again faced with what appears to be the same problem with another excavator of the same model. Both machines were around 1800 hours.
    I might add that the pressures are ok and adjusting the torque absorption settings make no difference apart from what it is designed to do. The fuel system appears ok and so does the motor.

    What I am saying is that the machine will operate as per normal and all of a sudden you have a major stalling problem,. Even to raise the boom by itself you have to be careful not to stall the motor 5minutes later all is ok.

    What I am asking is has anyone came across a similar problem and did you come to the same conclusions?? If not what am I missing??

    Regards Mike
     
  2. RobVG

    RobVG Senior Member

    Joined:
    Jun 20, 2009
    Messages:
    1,028
    Occupation:
    17 excavators and a stewpot of other stuff
    Location:
    Seattle WA
    We have a PC30MR-2. For what it's worth, the only engine problem I had was with the electric transfer pump. But it just stopped running altogether- didn't stall.
     
  3. Keith Powell

    Keith Powell Member

    Joined:
    Mar 7, 2018
    Messages:
    10
    Location:
    Monticello
    I have a pc50mr2 doing the same thing, I don’t want to spend $5,000 for a new pump, but it’s so bad now I can’t use machine, I have a farm and I absolutely depend on machine, I wish we could find a fix
     
  4. John C.

    John C. Senior Member

    Joined:
    Jun 11, 2007
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    11,713
    Occupation:
    Machinery & Equipment Appraiser
    Location:
    Northwest
    I haven't done much work on those so don't remember the type of monitor panel. Can you supply a photo and we can check to see how to get into the diagnostics of the machine if it has that feature?
     
    Vetech63 likes this.
  5. DK88

    DK88 Senior Member

    Joined:
    Jan 19, 2011
    Messages:
    320
    Occupation:
    Field service tech.
    Location:
    Ontario
    not possible from monitor.
     
  6. DK88

    DK88 Senior Member

    Joined:
    Jan 19, 2011
    Messages:
    320
    Occupation:
    Field service tech.
    Location:
    Ontario
    those little pumps are lemons. sorry to say but time for a new pump and a good flush
     
  7. Keith Powell

    Keith Powell Member

    Joined:
    Mar 7, 2018
    Messages:
    10
    Location:
    Monticello
    Pump is $5,000