"Automatic" Parking brake adjustment?

Discussion in 'Chevy Silverado Forum (GMC Sierra)' started by travisn, May 19, 2013.

  1. travisn

    travisn New Member

    I have a 99 Silverado that I just put all new brake components except the main cable and passenger side cable. I adjusted the shoes to where I could just get the rotor on.

    I can push the pedal all the way to the floor and sort of feel the truck slowing down, it definitely won't hold the truck in gear though. It seems if the pedal mechanism would 'grab' earlier it would be fine. I haven't been able to find a schematic or description of how it works or how I can adjust it, only 'your cables are bad' or 'change the shoes'. The adjuster in the middle is maxed out (and rusted in that position, haha), I could barely get the rear cables into the adjuster bracket after having everything apart.

    anyone?
  2. j cat

    j cat Active Member

    The disc rear brakes have a rotor that has a PARK BRAKE INNER DRUM . this inner drum wears out because the park brake shoes hold down clip is weak. the fix to prevent the shoes from moving around is to replace these hold down clips so they firmly clamp these shoes to the backing plate.

    the parking brake cable is not to be adjusted. if you adjusted it or it was adjusted before this causes problems.

    with NEW park brake shoes installed if the park brake does not hold the vehicle securely in drive with the vehicle stopped then the rotors need replacement with the park brake cable ears in the 1/3 position with the park brake firmly on . this is where the cables connect to the park brake adjuster at the backing plate.

    THIS IS A PARKING BRAKE ONLY AND IS NOT TO BE USED WHEN THE VEHICLE IS MOVING AT ANY TIME !
  3. Conlan Rose

    Conlan Rose Super Moderator

    To adjust the drums the procedure is usually to back up and keep tapping the brakes, but with all wheel disks and a parking drum I'm unsure.
  4. travisn

    travisn New Member

    J cat, you obviously didn't READ my post and just copy/pasted from somewhere else.

    EVERYTHING is new: rotors, shoes, hardware. I replace the left cable as it was seized, the right and front cable operate smoothly. I adjusted the star wheel until I could barely get the rotor on and off.

    I think there is something wrong with the automatic adjuster at the pedal

    - - - Updated - - -

    That's how normal drum brakes work, there is a mechanism that rotates the star wheel when the parking brake is applied when going in reverse, not the case here.
  5. j cat

    j cat Active Member

    I did not copy paste anything . I had the problem a long time ago when my 2000 was 1 year old under warranty and the dealership messed up my parking brakes . everything I stated earlier is what I did to correct my park brakes so that till this very day still work correctly and that is now about 11 years.

    your very vague statement I replaced everything did not say rotors. I took every thing as the cables/park brake shoes etc...

    now like I stated before where the park brake cable connects to the park brake adjuster/lever with the rotor on etc this ear should be 1/3 the way up in the park brake on . this should cause the park brakes to hold vehicle with new shoes and a new rotor.

    with the park brake off there should be slack in the cable this is the cable along the frame rail opposite the fuel filter..

    the dealership tech screwed up my park brakes by placing washers on that T bracket to make that cable pull tighter and that messed up that park brake self adjuster pedal in the driver pocket ... that what I was getting at when I said if that cable is adjusted it will screw things up,.........

    - - - Updated - - -

  6. shibby2oo8

    shibby2oo8 New Member

    There is a way to tighten just havent had to do it on one of these yet. Usually where the single cable splits to two under the drivers side there is a threaded bracket or some sort of tension device. I cannot find my manual anywhere but it should hold the truck idleing in gear. You may want to check the shoes again as they may have seated and lost adjustment.
  7. j cat

    j cat Active Member

    the park brake pedal assy is self adjusting. the cable out side the vehicle must be slack and if its adjusted that the threads showing are not about 50% you will kill the internal pedal self adjusting feature.

    I spent a great amount of time studying this flawed park brake design . I had to correct this myself. 10 years later I get a class action lawsuit letter which was successful where GM had to compensate those who had park brake failures prior to the warranty period ending.. the defective hold down clips on the shoes caused the park brake shoes to wear out at about 15-20,ooomi. then the dealership would bill you 200 or so for repairing/replacing the park brake shoes. many complained saying I never used the park brake how could it wear out !
  8. travisn

    travisn New Member

    Sorry, I didn't mean to come off as aggressive, but your response seemed very general.

    So there is supposed to be slack in the cables? Like enough to easily separate the rear cables from the front cable? So I could have them too tight?

    The adjuster bolt/nuts are rusted together, I didn't apply heat to try to get them apart because they were basically all the way tight so I didn't think loosening would help any. I still can't comprehend how the self-adjustment at the pedal works though. I guess I'm going to have to take it apart and check it out.
  9. j cat

    j cat Active Member

    I did not take it that way. I just said what I stated because this was a problem that GM basically screwed me on by messing up my park brakes.

    sounds like the adjusting cable next to the frame rail is the problem . you must back off that nut so that its at the 50% area not all the way tight. be careful not to damage the cable/threaded rod connection. wire brush the threaded rod clean so the rust is gone. then use penetrating oil and place a rag around this with the rag wet with the oil. after a few days try to back off the nut work the nut in/out not so much force that you break it . I used vice grip on the rod to hold steady as the nut is rotated.

    then with this adjusted properly work the park brake pedal many times then test. if this pedal does not adjust the pull on the park brake ears located at the shoe adjuster to the 1/3 position then you may need a new pedal assembly.

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