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tspeckin's avatar
tspeckin
Explorer
Jul 17, 2013

Park brake

I'm posting this for a friend in hopes of helping him out. I apologize up front if I don't know exactly what I'm talking about. He bought a used class c and used it this past winter on a trip to Fla. No problems. Last week he went to leave on vacation and the drive train was locked up. Apparently there is a brake inside the drive shaft that engages when the vehicle is put in park. It appears that there are electric switches that engage a hydraulic pump which applies the brakes. Anyway, the brake will not disengage. Any body out there know what I'm trying to explain and may know a remedy?
  • Thanks for all of your help. I forwarded this thread to him. Looks like you all got him on the right track. All of the mechanics that he contacted acted as though he was speaking a foreign language with this system.
  • MY last address on OLDUSEDBEAR (Roger Hopkins) is

    OLDUSEDBEAR@OEMYS-PERFORMANCE.COM
  • My mistake. It is a class A, 1999 Damon Challenger in a GM gas chassis.
  • Please post specifics: What chassis-- Ford or GM? What model year?
  • If this a Chevy chassis, Norm is probably right. I'm surprised to hear that it's a Class C instead of a Class A, however. One way to disengage it TEMPORARILY without things going BOING is to tighten the Locknut on the Actuator Shaft against the housing, then continue to turn it until it pulls the Shaft out enough to disengage the Brake. You might need to use a fender shim of the right size as a washer if the hole is too big for the Locknut to seat against it. As Norm said, take all precautions so the MH doesn't roll over you.

    Above all, get in touch with Oldusedbear before you let anyone touch it, as Norm said.

    Please keep us posted.
  • You are probably referring to a brake which clamps
    around the drive shaft when the selector is placed
    in 'PARK'. This is called 'Auto Park'. It was
    used because the motorhomes were to too heavy for the
    normal park pawl (gear) to hold them. This system is
    commonly controlled by the ROTTEN GREEN SWITCH. When
    it fails, the clamp around the shaft is locked in place.
    On this website, find OLDUSEDBEAR, and he is the EXPERT on
    this system.....he will help resolve the problem, which
    often requires replacing the switch. On my motorhome
    this system is front left, under the 'hood', and
    contains a plastic tank (small) for the fluid and
    a pump, and the famous switch. (It is possible that
    the tank is out of hydraulic fluid, so that the system
    cannot release the clamp/brake). A mechanic can go under
    the motorhome and remove the clamp/brake, but the driver
    will have NO PARK FUNCTION.......the R V will roll away.
    Blocks have to be placed under the tires to stop this
    danger. (Good luck !)

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