Originally Posted by jim8860
Well I just got back from a WWII weekend www.mamm.org
and the auto park brake light went on. I stop the MH and check things out and the parking brake seem at the time not locking up , so I guessed that the switch was bad. About 150 miles in to the trip home a brake smell arose right after a heavy stop to watch a pick up truck fliped up side down on the side of the road ( nobody was hurt luck) so I guessed it was the MH brakes. I drove home and thew the Mh in park and just about got out and the MH stared to roll down hill ( a small grade) in the driveway. After all this my question is this, I guess there is no park pin in a 1995 LY MH with a 4l80E trans, and the Auto park is the only source to park this in place right?. So where can I find some repair books or info besides the horror story on the famed nightmare of GM's Auto Park? any info woudl be real helful. Thanks Jim
Okay, getting back to your original question. I have had to replace the pressure switch for the parking brake on those rigs, the switch will blow out, and start leaking hydraulic oil, until there is none left in the reservoir, at which time the parking brake will apply, until it is completely burned off. If you crawl under your unit, on the curb side, around the area where the step is, you will find a largish metal cover held on with 4 bolts mounted on the inside of the frame, between it and the driveshaft. Take the cover off, it should be 9/16" bolts, and locate a pressure switch that resembles an A/C low pressure cutoff switch. If you unplug the switch, you will most likely find a bunch of hydraulic oil inside the plug. You can unscrew the switch, and go to your local GM truck dealer. For around $60 or so, you can get a new switch, and on the way back home, pick up a couple of quarts of hydraulic oil, you will need it.
Crawl back under the motor home, install the switch, and locate the fill for the hydraulic reservoir. Fill the reservoir, reattach the metal cover, and start the motor home. Put the motor home in gear, then put it back in park. check to see if the motor home tries to roll away, if it doesn't you got lucky, and don't need to go any further.
If it rolls away, you will need to replace the parking brake shoes.
That is another can of worms, that will require removing the front of the driveshaft, and the parking brake drum.
After doing that, you will most likely notice that the shoes are worn completely away. If not, they are so far oout of adjustment, that they will not hold. If they are adjustable, try adjusting the shoes out until they will not allow the motor home to move. If you can't adjust them, you will need to make a second trip to your Chevy truck dealer, for new parking brake shoes.
The shoes should be easy to replace, just make sure the actuator cable is attached correctly before reinstalling the drum.
After all this, you should have park again.
Good luck with it, and I hope it is the switch, it is the least expensive fix.