Case 621D

1. #1Steve 6502013-09-16 21:07

   electrical or hydraulic issue

2. #2Tinkerer2013-09-17 07:23

   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.

3. #3Alan Pitts2013-09-17 22:15

   Brakes won't release. Calipers not froze up. Where do I check for voltage for releasing the brake?

4. #4Alan Pitts2013-09-17 22:24

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

5. #5digger242j2013-09-18 01:55

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

6. #6gggraham2013-10-05 23:52

   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.

7. #7SHELBY BRYANT2018-10-10 22:28

   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

8. #8Vetech632018-10-11 08:31

   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.

9. #9SHELBY BRYANT2018-10-11 12:51

   i will check the pressure, where is the pressure switch located.

10. #10Vetech632018-10-11 14:42

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

11. #11Coy Lancaster2018-10-16 10:34

    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.