Anybody ever turned a parking brake drum?

[pago cruiser]

Seems the deeper I dig the more cr@p I find.

Pulled the autopark drum, as it could not hold the coach on our maybe 20% driveway. Sigh. It looks like the brake either engaged whilst they were driving, or they forgot to release it. The drum was blue from the heat, and somewhat egg shaped. It also went on long enough to apparently heat treat the drum.

Put it on a friends lathe, and we had to turn about 60 thousandths to get it round again; maybe 10 thou at a time; that metal was hard!

Good thing the tranny seal was leaking, as it kept the shoe to drum interference well lubed.

JHC. I think it will be ok, as it is not as if this is bringing the coach to a stop from 80 mph..., generating massive amounts of heat.

But does anybody know the specs on turning this?

I did a check with a local shop who only deals in AC Delco parts. New shoes will be here tomorrow, but he struck multiple deadends on every possible variation on the drum. Seems hard to believe GM would make this stoopid little drum just for these P30 motorhomes. I'm thinking that somewhere, somebody has found a match?

I just found this...
http://store.stepvanparts.com/EMERGE...MBLY-10975.HTM

but it does not appear they list the drum. Guess I'll give them a call tomorrow.

[scamp]

It's been a long time since I worked on these trucks (p30)maybe 30 years ago so I might not be accurate on measurements but from what I remember the maximum diameter was either 11inches plus 60 thousandths or 90 thousandths of the drum , ( the second measurement is the one I think is correct)it was usually written on the drum,outside edge. Hope this helps.

Don

[scamp]

Here is a online manual for GM motor homes , I didn't see any specs on the parking brake but lots of other info,www.gmcmi.com

[pol]

I pulled my 1995 Land Yacht over due to a disconcerting odor. While stopped the emergency brake froze up. There was not a noticeable drag on the RV - but it froze solid. I received a Good Sam free tow to a local truck repair shop and the parts and labor came to $600.

[TomKirk]

Is this the drum behind the tranny?? If so, buy a new one. They're not that expensive.

From what you've said, the drum is cooked and mustn't be re-used. No matter how much you tighten the shoes and/or park brake rachet, the new brake lining will just slip. In other words, your parking brake will be useless.

Get a new drum. You'll be glad you did.

Tom

[pago cruiser]

Thanks all.
I did get confirmation from another couple sources that the max is usually 90 thou; usually indicated on the drum - but not the autopark drum.

I checked out that online manual -cool stuff - but for the bonafide GM old-skool fiberglass Coach. Interesting reading though. One of the tech references took me to a 130 page pdf on the GM Coach parking brake system. Which is about as lame as the autopark on ours. Several different versions, none of which work well. A few half-ass recalls. A very good possibility of mixing up of parts, etc. IMHO, GM really screwed the pooch on all parking brake systems from the 70's right up to 2005 (I think), the last year of the autopark. Hard to believe they have never been held accountable for these crap designs foisted on the public....

$600? Yikes. Glad it was not worse; there are so many freaking stories about the havoc this sh!t system creates when (not if) it fails. Once I get the shoes/drum/cable system back together, I am seriously thinking of float testing the entire autopark hydro system. Our 96 still has the manual parking brake; which is relatively foolproof.... I just bought a new cable for it for $50. And I just today found a tranny with a donor parking pawl system; pulled it myself so I now know how it works - pretty simple. I'll do another thread on it. My thinking is that this was standard on Coaches up to 16000 GVW. Our GVW is 16500, but more than half loaded (the coach, not us...) we are at about 14500. So I am 10% under the max weight they use(d) this on.

I tried very hard to find a new drum b4 I decided to try turning the one I have. Prolly 4 hours on the phone thru at least 6 different vendors. Per the post earlier, I only turned the drum down about 60 though - I should not be at the max by most data that I can find. And besides, mine is now heat strengthed!!

That said, I finally called the Mill Valley place, and it seemed I struck out again. But as I kept pestering the poor guy, he remembered that ??? (sorry, I forget what company) bought the Workhorse chassis company a couple years ago, and he saw a drum on the driveshaft when looking thru a parts catalog. It measures correct (11" x 2"), and the bolt holes look correct. So for $60 I'll have one next week to compare.

If you have any other source for the drum, I would love to have the reference. As I indicated in an earlier post a few days ago, sure would be nice to have a sticky post documenting common part numbers and sources...

[TomKirk]

Q: What year is your P-30?? Have you contacted a Workhorse dealer??

FYI - In the year 2000, GM sold their entire P-series truck line to Workhorse.

Tom

[pago cruiser]

We are a 96.
Our local Chevy dealer is the defacto dealer for anything now.

Yes, when Chevy sold the P30 to Workhorse a long time ago, they came out with the W42 chassis.

With the new owners (Amp Electric Vehicles), apparently now re-incarnated as "Workhorse Group Incorporated", the newer (but now old...) W42 is now supported under "Legacy" status.
http://workhorse.com/our-chassis/legacy-chassis

From the new Workhouse site:
AMP acquired the Workhorse brand and the Workhorse Custom Chassis assembly plant in Union City, IN in March of 2015. The asset acquisition made the company an OEM and enables the company to manufacture new, medium-duty truck chassis in the 14,500 to 23,500 GVW class.
In March of 2015, AMP formally changed its name to Workhorse Group Incorporated (OTCBQ: WKHS).

If W42's are now "Legacy" equipment, I guess P30's are pretty much orphans... Which is why parts are so bloody hard to get; coincidentally, it makes the responsibility trail for cr@p designs like the autopark a deadend. There is no one left who can be held accountable...

[loreepeter]

Look for my thread on auto Park. I stayed where I bought new shoes. If you cannot find it. Post the message. Otherwise I will try to find it. The shoes are very easy to buy. As I recall there available at many auto parts store. Sorry cannot reference the part numbers right now Perhaps you can search my previous posts and the information will be in there. On vacation right now.

[pago cruiser]

No problem - found the shoes; we have a local AC Delco parts store was able to special order them.

The problem was the drum. But with the Mill Supply order, I should find out next week if it will work.