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Case 621D

Discussion in 'Wheel Loaders' started by Alan Pitts, Sep 16, 2013.

  1. Alan Pitts

    Alan Pitts New Member

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    Location:
    Wellington
    Parking brake won't release.
     
  2. Steve 650

    Steve 650 Well-Known Member

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    Mar 23, 2013
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    Canada
    electrical or hydraulic issue
     
  3. Tinkerer

    Tinkerer Senior Member

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    Location:
    IL. USA
    It could be a seized caliper. You can open the bleeder valve and release any fluid pressure that may be holding it . If the caliper doesn't release, then it will need servicing. Be sure the machine cannot move when you are trying to release the parking brake. If this thread was in the wheel loader forum you would have a better chance of having someone with 621D experience read this.
     
  4. Alan Pitts

    Alan Pitts New Member

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    Location:
    Wellington
    Brakes won't release. Calipers not froze up. Where do I check for voltage for releasing the brake?
     
  5. Alan Pitts

    Alan Pitts New Member

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    thanks ; it is a electrical problem I reposted this under wheelloaders
     
  6. digger242j

    digger242j Administrator

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    I merged the two different threads. Carry on...
     
  7. gggraham

    gggraham Senior Member

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    Occupation:
    Licensed Heavy Duty Equipment Mechanic
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    What are your brake pressures? The test ports are on the LH side of the machine under the plastic cover just behind steps. Seen lots of bad brake charging valves on these things.
     
  8. SHELBY BRYANT

    SHELBY BRYANT Member

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    Oct 6, 2018
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    Location:
    clewiston
    i am checking a 621D and the parking brake on the dash is on it will not go forward or reverse. any suggestions on that
     
  9. Vetech63

    Vetech63 Senior Member

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    I would check your brake pressure first. Remove the small cover attached to the lower right of your cab. There should be a test port for your brakes. I don't remember exactly but I believe it should be between 1800- 2000 psi. If you have the brake pressure, then its more than likely a electrical problem. There is also an accumulator valve that the brake pump output line goes into first, that's where the pressure switch is. I had one of those valves grenade on a 621.
     
  10. SHELBY BRYANT

    SHELBY BRYANT Member

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    Location:
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    i will check the pressure, where is the pressure switch located.
     
  11. Vetech63

    Vetech63 Senior Member

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    Location:
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    The switch for the brake light is in the accumulator valve, inside the main frame right side of the machine next to the engine.
     
  12. Coy Lancaster

    Coy Lancaster Senior Member

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    Occupation:
    service tech
    Location:
    Arkansas
    There is a serial number break on the 621D which do you have early or late s/n?
    The brake accumulator control valve is built into the pedal valve on the D series and the accumulators are under the cab. Do you have any warning lights on in the cab? Make sure that your brake light is going out before you try and disengage park brake, always hold brake pedal down before you turn park brake off and leave shifter in neutral and if you have the FnR switch on the loader control handle make sure it's in neutral position. I'm sure you know all this but just some issues to check.