W/24 Park Brake Not Holding

[arknphyl]

I have a 2005 Newmar Mountain Aire W/24 W/H. The AAPB has gradually gotten weaker, to the point it just doesn't hold anymore. Is there any adjustments or Maintenance (that an old man) can do to help this problem. I suppose this is a disk / calipers, and hyd pressure to unclamp.

[DriVer]

Quote:

Originally Posted by arknphyl I have a 2005 Newmar Mountain Aire W/24 W/H. The AAPB has gradually gotten weaker, to the point it just doesn't hold anymore. Is there any adjustments or Maintenance (that an old man) can do to help this problem. I suppose this is a disk / calipers, and hyd pressure to unclamp.

The in-line driveshaft mounted brake is applied under a great amount of hydraulic pressure. I would go and have the brake evaluated/adjusted by a service center.

[NoTow]

I also own a 2005 Newmar workhorse 24 chassis (Kountry Star) I am having the same problem. If you check the Workhorse Motorhome club newsletter,Volume lll issue 3 dated September 2005.Pg 3 Describes how the new Auto Park system is designed. It stats that The foundation brake is a drum brake mounted on the rear of the transmission. activated by a spring loaded chamber mechanically applying the brake. A hydraulic cylinder from an electric powered pump releases the brake.
I have tried to contact Workhorse on this issue and have not yet received a reply. A local Allison/Workhorse repair facility also requested information.Over 2 weeks ago and he has not received a reply.
If I find anything I will post information.
By the way the design of this system was to activate the brake in the event of failure !!!! Not create a potential runaway hazard.
Lets hope we can get some resolution

[edgray]

Gentlemen: Please note there is a link to the 2009 "Chassis guide" at the top of this forum. It is a huge download, but if you will refer to pages 175 thru 178 of that CG, you will learn much about your J-72 AAPB being discussed here. There is even a schematic.

The OP stated his had gotten "weaker" over time, and that MAY be an indication that the brake pads have become worn down and need to be replaced.

Since this device is the only means of keeping your MH "parked" when you shift to "P" ( unless you deploy your jacks or chock your wheels ), I think a prudent owner will have it checked by an ASC who can properly diagnose the problem and make repairs as needed. Ed

[arknphyl]

Thanks Guys for your help. More than anything just trying to understand how it is built. I, like most of you I suppose, will do my own service if possible.
It sure is nice to have a forum, with people that try to help. Will try to post all that I discover.
Also don't have total confidence in my area service center.

Thanks again

[tropical36]

Quote:

Originally Posted by edgray Gentlemen: Please note there is a link to the 2009 "Chassis guide" at the top of this forum. It is a huge download, but if you will refer to pages 175 thru 178 of that CG, you will learn much about your J-72 AAPB being discussed here. There is even a schematic. The OP stated his had gotten "weaker" over time, and that MAY be an indication that the brake pads have become worn down and need to be replaced. Since this device is the only means of keeping your MH "parked" when you shift to "P" ( unless you deploy your jacks or chock your wheels ), I think a prudent owner will have it checked by an ASC who can properly diagnose the problem and make repairs as needed. Ed

Might I ask why these pads (disk brake on the J72 version, right?) might be worn unless they've been dragging for some reason and this is only a symptom to the real problem like maybe driving the coach with a malfunctioning brake applied. I mean you can't hardly wear out a brake thats not used for stopping!
Also if you or Driver might answer the question of when the W24 shed the AP system in favor of a tranny parking pawl and a manual foot pedal, which I'm thinking also coincided with the six speed Allison?

[arknphyl]

I had not registered With W/H. I am the 2nd owner, and couldn't download guide unless I was registered.I did this on 9/15/10 and am still waiting for a reply from W/H, so that I may download guide. As soon as I can check the guide out I will attempt to come to a conclusion, what to do.
However this sounds reasonable enough(that it shouldn't wear out just being used for a park brake). I just don't know what has caused the problem, but hope to find out soon.

[edgray]

Quote:

Originally Posted by arknphyl I had not registered With W/H. I am the 2nd owner, and couldn't download guide unless I was registered.I did this on 9/15/10 and am still waiting for a reply from W/H, so that I may download guide.As soon as I can check the guide out I will attempt to come to a conclusion, what to do. However this sounds reasonable enough(that it shouldn't wear out just being used for a park brake). I just don't know what has caused the problem, but hope to find out soon.

arknphyl: I am NOT making any type of accusation here, but it is entirely possible to overpower the AAPB with application of sufficent throttle. The pads may have worn down from the coach being driven without releasing the brake. Ed

[arknphyl]

I thought(a bad thing for me) that I had no PB at all but actually it is actuating and is hard to push on level pavement. Will roll easy with brake off in neutral. It may have been driven with brake on. Can't say for sure since I am 2nd Owner. PB will not hold in drive or reverse,even Idling. I suppose I had never checked if it would. but I would hope that it should.

Thanks to Several of you for your help. Hope I can repay somehow.