1996 Workhorse p-30 autopark break failure

[Ed L]

My 1996 Safari Trek broke down and had to be towed. Tow truck driver had hard time towing the RV but got it to repair shop where they put in a new fuel pump and rear brakes. The RV worked fine for a year but now after a 500 mile trip it rolls when put in park. The emergency break doesn't work either. Checked black box & RGS switch was leaking. Replaced the RGS and the unit now engages the cable and it moves aprox 3-4 inches but the RV still rolls. What are my next steps to fix it?
Ed L
elux@fuse.net

[edgray]

Originally Posted by Ed Lux

My 1996 Safari Trek broke down and had to be towed. Tow truck driver had hard time towing the RV but got it to repair shop where they put in a new fuel pump and rear brakes. The RV worked fine for a year but now after a 500 mile trip it rolls when put in park. The emergency break doesn't work either. Checked black box & RGS switch was leaking. Replaced the RGS and the unit now engages the cable and it moves aprox 3-4 inches but the RV still rolls. What are my next steps to fix it?
Ed L
elux@fuse.net

I'm guessing the brake shoes inside the DS mounted PB have worn down to the point they won't hold. No way to know if the tow driver wore them down. I think they are adjustable, but may be beyond continued use.

The best source for FREE info on the J71 AAPB is HERE: www.rvautopark.com



A good source of parts is either Mill Supply or at www.urvp.com



Good luck!

[n2zon]

Originally Posted by Ed Lux

My 1996 Safari Trek broke down and had to be towed. Tow truck driver had hard time towing the RV but got it to repair shop where they put in a new fuel pump and rear brakes. The RV worked fine for a year but now after a 500 mile trip it rolls when put in park. The emergency break doesn't work either. Checked black box & RGS switch was leaking. Replaced the RGS and the unit now engages the cable and it moves aprox 3-4 inches but the RV still rolls. What are my next steps to fix it?
Ed L
elux@fuse.net

These things really don't wear out on their own. It sounds like one or two things, or both, happened. The first is that the tow driver might not have released the parking brake.


The second is that the autopark system could have failed while you were driving. The effects of either or both would be the same. Burned shoes and a glazed drum.


The autopark brake does not have enough authority to lock the wheels up, and a tow truck could easily overpower it. Heck, the coach's engine can overpower it. If it comes on while driving on the highway, you might not even notice until it's toasted (I smelled brakes, and by the time I got stopped the drum was cherry red).



It's actually good that it won't lock the rear wheels; a spin in coach induced by locked rear tires would likely cause it to roll over in short order. Even if it didn't roll, you'd be blocking all three lanes as it went around...if you were lucky enough to stay on the road.


Needless to say chock the wheels before you crawl under the coach. To pull the drum and inspect the brake, you need to remove the drive shaft and loosen or disconnect the autopark cable (all 7,206 turns of it--yes, I'm exaggerating). Then, remove the center bolt that holds the drum on, IIRC, and pull off the drum. See what's in there. If the answer is a glazed drum and fried shoes, you can get new shoes. Last time I tried to get a drum, they were no longer available. However, you can remove the glaze with patience and 100-grit sandpaper. Or, if it's within the wear limits, you can have it cut just enough to get a fresh surface by a machine shop. Stress that new ones are not available and you want the lightest possible cut.




Check to make sure the actuating cable housing isn't partly melted where it enters the assembly forward of the drum. If it is, replace the cable.



Reassemble, adjust, and check the autopark operation. The "emergency brake" activates the same brake, but with a cable. Make sure it works, too, and holds the coach against moderate throttle in Drive.


I've probably forgotten something or another. The service manual is helpful. (No idea whether it's still available. I had the full set, but I no longer have them since I sold them with the coach.)



If you are not REALLY SURE you can do all this, bring it to a truck mechanic. Despite its failings, it's a critical system for safety.



Finally, DO NOT rely entirely on the "emergency brake" in an emergency. It is designed as a parking brake. It just isn't very strong, and if you're going downhill I suspect it would overheat too fast to do much good on its own.



I truly detest the autopark system. Had I known about it when I bought the coach (which I no longer have), I'd have made another choice. You can find out lots about autopark failure modes with a Google search. Some enterprising people have redesigned it to work better, but I wasn't that adventurous.


HTH...

[George Schweikle]

Sadly, the Autopark help site appears to be inactive. Roger Haag (old used bear) apparently shut down his wonderful website.

To the OP, the Autopark brake drum is stamped sheet steel, not cast iron. However parts are available on the step van parts site https://www.millsupply.com/

The autopark system isn't the disaster some people believe, but you need understand how to maintain it. For Safari Trek autopark assistance, see the TrekTraxs site Login you will find lots of information and help.

Originally Posted by edgray

I'm guessing the brake shoes inside the DS mounted PB have worn down to the point they won't hold. No way to know if the tow driver wore them down. I think they are adjustable, but may be beyond continued use.

The best source for FREE info on the J71 AAPB is HERE: www.rvautopark.com

A good source of parts is either Mill Supply or at www.urvp.com



Good luck!

[96Bounder1st]

Try this google search for more info.

Okay-i-solved-the-auto-park-brake-problem-

Good luck

Terry

[n2zon]

Originally Posted by George Schweikle

Sadly, the Autopark help site appears to be inactive. Roger Haag (old used bear) apparently shut down his wonderful website.

To the OP, the Autopark brake drum is stamped sheet steel, not cast iron. However parts are available on the step van parts site https://www.millsupply.com/

The autopark system isn't the disaster some people believe, but you need understand how to maintain it. For Safari Trek autopark assistance, see the TrekTraxs site Login you will find lots of information and help.

I stand corrected on drum availability (assuming the Step Van drum is the same as the P30 drum)! No auto parts or truck parts places near me could source them when I wanted one.


I'll be happy to agree to disagree about whether or not the system is a disaster. ;-)

[edgray]

Originally Posted by George Schweikle

Sadly, the Autopark help site appears to be inactive. Roger Haag (old used bear) apparently shut down his wonderful website. ........

Sure sorry to hear that, I didn't know. While trying to verify, I did find this tidbit that Roger apparently created some time ago: http://www.rvautopark.com/wp-content...AKE-SYSTEM.pdf


Maybe IT will help some......

[edgray]

Originally Posted by 96Bounder1st

Try this google search for more info.

Okay-i-solved-the-auto-park-brake-problem-

Good luck

Terry

That thread was started in 2014, but contains good info. It can be found HERE: https://www.irv2.com/forums/f22/okay...em-195374.html

[George Schweikle]

Well, yeah, the autopark can be a disaster if it lets you down. I'm lucky to have not had that happen. One kinda wonders if the world would be a better place if GM had just strengthened the PARK pawl in the automatic transmission instead of spending all of the time inventing autopark

Originally Posted by n2zon

I stand corrected on drum availability (assuming the Step Van drum is the same as the P30 drum)! No auto parts or truck parts places near me could source them when I wanted one.

I'll be happy to agree to disagree about whether or not the system is a disaster. ;-)

[edgray]

Originally Posted by George Schweikle

Sadly, the Autopark help site appears to be inactive. Roger Haag (old used bear) apparently shut down his wonderful website.........

I am happy to report the above post is incorrect.



After trying the site myself, I was convinced that George was correct, but I decided to reach out to Roger via email fearing that the site was down because something had happened to HIM.



Roger has replied to my email expressing surprise at my questions and he assured me the site IS NOT shut down, and I just confirmed that it IS WORKING "now", and I'm sure George will also be glad to know the outage was apparently temporary.


For those with J71 AAPB systems, FREE info remains available at: AutoPark parking brake system help, troubleshooting, and repair

[LETMGROW]

Originally Posted by edgray

I am happy to report the above post is incorrect.



After trying the site myself, I was convinced that George was correct, but I decided to reach out to Roger via email fearing that the site was down because something had happened to HIM.



Roger has replied to my email expressing surprise at my questions and he assured me the site IS NOT shut down, and I just confirmed that it IS WORKING "now", and I'm sure George will also be glad to know the outage was apparently temporary.


For those with J71 AAPB systems, FREE info remains available at: AutoPark parking brake system help, troubleshooting, and repair

Ed, thank you so much for the investigation and update. I too was concerned as Roger had been a big help to me when I had a problem with my Auto Park and Roger's advice saved the day (and a planned vacation) for me.
Roger is one fine individual.

When I first saw the news Roger's site was shut down I tried it also. It would not come up for me either.
Lynn

[n2zon]

Originally Posted by George Schweikle

Well, yeah, the autopark can be a disaster if it lets you down. I'm lucky to have not had that happen. One kinda wonders if the world would be a better place if GM had just strengthened the PARK pawl in the automatic transmission instead of spending all of the time inventing autopark

Ours failed on the Long Island Expressway at 65 mph in heavy traffic (is there any other kind on the LIE?), while towing. The warning light didn't come on, and the coach did not slow perceptibly, so the first clue was the faint smell of burning brake shoes. I pulled over at the first safe place to see what the smell was about, which was a few miles farther East. The drum was bright red. I waited 20 minutes for it to cool enough to disconnect the threaded rod. It melted the plastic housing on the cable, which also had to be replaced.

The only silver lining was that it did not cause a fire.

I got it working, reconditioned the badly-glazed brake and drum, and disconnected it. I used the foot pedal the engage the parking brake instead until we traded the coach.

The basic idea behind the design is OK, I suppose, but it should have incorporated an interlock so it would not engage unless the coach was in Park, in my opinion. Having it fail with the coach stationary would have been much less exciting, less hazardous, and far less annoying, and would not have damaged the brake itself nor the cable.

Ours had an Allison transmission. I'm not sure whether Allison uses parking pawls, but an expert I am not!

[George Schweikle]

Yep, the website is working and that is great news. Thanks. I have benefited greatly from Rogers's expertise and will pass this on to the Safari Trek forum where many owners have autopark.

Originally Posted by edgray

...
Roger has replied to my email expressing surprise at my questions and he assured me the site IS NOT shut down, and I just confirmed that it IS WORKING "now", and I'm sure George will also be glad to know the outage was apparently temporary.....

[Ed L]

I changed the drum breaks and adjusted the shoes so it holds on a steep hill in park. Autopark Break releases fine but the Autopark light is now on. The interesting thing is that this is the first time that light has come on. Before replacing leaking RGS the only light that was on was the Emergency Park Break which has gone off but the Autopark break light remains on. What am i missing now? thanks for all the advice, really appreciate it.