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dalehelman · 11-20-2009, 07:27 PM

I successfully replaced my defective J72 Auto Park brake with a direct fit manual hand brake. This is the same E brake that GM Workhorse has used on there step van chassis ie. bread trucks, service vans for years. When our Auto Park failed and caught fire. The replacement from WH was going to cost $2,400 just for the brake assembly alone. Assuming the pump and actuator assembly were OK. If the actuator assembly were the cause the price for it could be another $2,000 plus labor on both. The manual replacement has cost less than $350 and that included all new parts. Only basic hand tools were required. I did have to fabricate a mount for the brake lever. The J72 is the new improved version of the Auto Park, and much different than the early style J71. Although this replacement should work on any Auto Park.

max49 · 11-20-2009, 07:42 PM

I believe there are quite a few of us who have thought about doing this. You made it sound like it was a fairly easy job.

Could you give us some more information as to what parts you bought and where you got them from. Did you just buy parts that were for a specific vehicle?

Some pictures of the working parts would be great too.

dalehelman · 11-21-2009, 10:31 AM

here is the parts web site with pictures:Parts that fit Workhorse Chassis

EngineerMike · 11-21-2009, 11:23 AM

We had a 1995 P chassis w/AutoPuke. Our earlier P30 had a manual lever operated brake that actuated via cable. Over many years of operation the lever's cable frayed & jambed. I replaced it w/minimal brain damage. Other than that, the cable/lever assembly was simple and effective.

No reason that any of the later AutoPuke's couldn't be replaced w/lever operated, simple, cheap alternatives.

Brilliant!!!

max49 · 11-21-2009, 05:07 PM

Quote:

Originally Posted by dalehelman

here is the parts web site with pictures:Parts that fit Workhorse Chassis

Thanks for that link for a source for P series parts. I can't see any thing for the autopark parking brake or for the manually applied hand or foot parking brake.

DriVer · 11-21-2009, 05:24 PM

Questions about the J71 Auto Park? Contact OldUsedBear!

He's the resource to go to in regards to anything Auto Park Pre-J72.

dieselclacker · 11-21-2009, 05:33 PM

My son-in-law has a 2002 Workhorse P-32 chassis Fleetwood Terra motorhome with the GM 4 speed transmission, it came standard equipped with foot operated parking brake. Parts are available from Chevrolet for this foot operatred system.

Dieselclacker

dalehelman · 11-21-2009, 05:43 PM

Quote:

Originally Posted by dalehelman

here is the parts web site with pictures:Parts that fit Workhorse Chassis

After you click on the site. Click on stepvan parts all categories. Then click brake hwd. Then brake hwd GM Workhorse. Last emergency brake 19.5.

DriVer · 11-21-2009, 06:12 PM

dalehelman, Could we find out your year, make and model of chassis please? Thanks!

EngineerMike · 11-21-2009, 06:32 PM

I continue to like the idea of going full manual on the AutoPark, but there will be some fabrication needed on both ends.

In addition to a mount plate for the grab handle pictured, to get it in a structurally stable but still accessible (and yet not in the way) location, you will need a stay bracket at the drum brake end, and probably some hardware mod at the drum brake pull point as well.

A foot pedal, fully mechanical, would be even better.

DriVer · 11-21-2009, 07:40 PM

Quote:

Originally Posted by EngineerMike

A foot pedal, fully mechanical, would be even better.

EM, Trying to provide systems that fit all types of drivers is the thing that drives how these vehicles are built and supplied with sub systems. I hope you will agree with that.

The task is to secure the vehicle from moving.

A J72 can be applied by any driver and it will yield the same result. The vehicle will be parked and immovable.

A vehicle equipped with a parking pawl and a foot brake can be applied by any driver and it will yield the same result. The foot brake in this instance becomes a secondary system.

Here's the problem. A vehicle with a GM 4 speed and an auto apply brake does not have a parking pawl. Remove the the J72 and go with a foot brake or a commercial hand lever and the parking brake will not be capable of being applied in the same manner with the same result consecutively over the period of time by any driver. The manual brake will require adjusting more often than a J72 and I would expect that the holding capability of the brake will diminish in a short period of time.

Any hand brake that I have used over the years most often required a twist on the adjuster before a good yank.

If a person has a W24 with a J72 and elects to go with a manual hand brake, I really can't buy into that technology. Large vehicles weighing 30K GCWR need excellent brake systems and the J72 works well in that application.

Don't get me wrong, I think that replacing a J71 with manual brake after all the failed pressure switches and underway application seems like a viable option and a God send.

Now that said, Brazels has an air applied J71 direct replacement called an Ultra Stop. I bet that an Ultra Stop can be applied by any driver, with the same result each and every time.

Those are my concerns about manually applied parking brakes on a recreational vehicle. If nobody else if ever going to drive that vehicle who cares! If there's a remote possibility that a vehicle might be sold or traded in at some point, I wouldn't feel too good about leaving the hand brake in a motorhome.

The auto apply brake technology has not been totally eliminated in all Workhorse products, The W18 still has a J72 and the UFO has an HPB Auto Apply Brake (not a J72). All other Workhorse motorhome chassis have parking pawls and foot brakes. (except R-Series)

dalehelman · 11-22-2009, 01:22 PM

Quote:

Originally Posted by DriVer

dalehelman, Could we find out your year, make and model of chassis please? Thanks!

2005 Terra with the medium duty P32 chassis. With 17,000 GVWR

dalehelman · 11-22-2009, 01:34 PM

If I had it to do over again I would have let it burn. Then I'd buy a Ford.

DriVer · 11-22-2009, 02:14 PM

Quote:

Originally Posted by dalehelman

2005 Terra with the medium duty P32 chassis. With 17,000 GVWR

Thank you! Beginning in 2005 17,000 pounders were being equipped with J72s. You are the first that I have heard of that has replaced the J72.

I would urge you to do what the commercial drivers do and bring wheel chocks. You may find them to be handy at some point during your travels. When I bought my W22 from Arlington RV out of East Greenwich, RI, they provided me with a huge rubber wheel chock. I never did get a chance to use it and it sat in my storage compartment for over a year before I relegated it to shore duty.