J71/J72 Auto park alternate parts solution

[Bella123]

While researching what to do if Auto park brake system loses hydraulic pressure, I came across another rv owner with workhorse, and they did manual brake system with parts from stepvanparts.com, substituting the inexpensive hand pull lever and cable for the expensive hydraulic complication. No photos or further details, any thoughts from you experieced rivits?
Being new at this, the stories of Auto park drama and expensive inconveinent repairs after towing, Just because the parking brake engages while driving seems crazy. My 2005 seems to be the j72, but if it engages from loss of pressure, now what?
Robert

[loreepeter]

We removed all hydraulic parts / lines for the brake. Replaced shoes on driveshaft brake. Installed foot / cable / brake ...to driveshaft brake.

To park: depress foot brake to apply
To drive: depress foot brake to release

Holds mo ho PERIOD.....

Will install electric reminder to Apply. And release.

Did ourselves...easy.

Many pounds lighter...same cable / distance travel....to apply shoes at driveshaft.

[Bella123]

Great to hear it's possible. Might you be willing to share parts you needed, where you got the parts and a photo or two to help the rest of us. Any suggestions greatly appreciated. Thanks very much!

[loreepeter]

Yes, of course. I'll try to compose a step by step.


Sent from my iPhone using Airstream Forums

[loreepeter]

Airstream Land Yacht (officially 2003 per VIN) 30’ no slide out. Original owner.
PROBLEM: PARKING BRAKE DID NOT WORK. NO ‘LOCK UP’ ….JUST STOPPED HOLDING.
RESEARCH. DECIDED TO REMOVE ENTIRE SYSTEM AND REPLACE WITH A MECHANICAL SYSTEM. 30 X 70 BUILDING with cement floor. Placed large solid hardwood blocks about 18” x 18” x 6”under hydraulic levelers. Raised moho up to the limit of the levelers. Cribbing under the entire moho at frame areas with no vertical space. Large pads placed under all wheels. Studied the entire shoring and cribbing for any possible movement. All batteries disconnected, ends of battery cables enclosed and tied to safe areas. Much fluorescent lighting.

remove pin holding cable from hyd piston.
remove hyd piston, electric, hyd lines [covered lines]
support drive shaft, disconnect at trans brake bell, carefully move out of the way & tie off.
Remove brake bell to expose brake pads.

how do I add a photo?

[Bella123]

Great write up so far!
I believe to add photo, below the write up, go 'additional options' , 'attach files' . Select 'manage attachments' , 'upload files from my computer' , and then select the location on the computer (or device) and name of the photos and you will see the bar on the top of the window change. At the bottom, select 'close window' , when all the photos are added, then post normally. I just tried it with my tablet since we are on the road, and it seemed to work.
Thank you very, very much for sharing!!!

Robert

[dznf0g]

May I chime in here? I do not have a moho, but I do have a history with the auto-apply park brake.

There are 2 reasons that it was used in the RV application: the weight of the larger units, when parked on a hill, will make it difficult to get out of park, unless the park brake is applied. If it were left up to the driver, many would not manually apply; the second reason...again, on the larger units, the parking pawl in the transmission may not be robust enough to prevent a fracture and subsequent roll away, again when parked on a hill.

If you are going to convert to a manual system, please install some kind of warning when the brake is not applied that is soooo irritating that any driver will be inclined to apply the park brake manually. Please think of the next owner who doesn't know any of this, as well.

[Bella123]

Thanks, good points. Question - if hydraulic failure, how are you going to get driving again without climbing underneath and pulling drive line to remove brake, and then put drive line together again? We go places where triple A, or tow is unlikely to be available. That is the reason I am asking how to save myself.
Thanks very much!

[dznf0g]

There is no other way. FMVSS requires that automatically applied brakes must fail to the engaged position.

However, IIRC, (and I may not) the double nutted adjustment at the pump actuator may have enough adjustment in it to pull the brakes "off". I seem to recall there is another adjustment as well, in the cables/linkage. It's been 20 years.....and I don't have service manuals anymore.

[loreepeter]

BRAKE SHOES: STANDARD ITEM, AVAILABLE AT MANY AUTO PARTS STORES,
NAPA # TS 228, 1 SET, $23.40 PLUS $7.00 CORE CHARGE WITH AAA DISCOUNT
NEED JUST 2 SHOES TO MATCH THE ORIGINAL, RETURNED THE UNUSED AND OLD SHOES…..TOTAL LESS THAN $ 25, …..MATCHED ORIGINAL INSTALL. . EASY CLEANUP AND INSTALL….TOOK PHOTOS BEFORE DISASSEMBLY TO ENSURE EXACT INSTALL.
CHECKED CABLE….LIKE NEW……PULLED IT BOTH WAYS, SLID VERY EASY. THEN INSTALLED CABLE………PULLED IT….SHOES MOVED EASY AND RETURNED EASY. ONLY NEEDED A LITTLE OVER 1 “FOR MAXIMUM HOLD POSITION. [BRAKE ‘ON’].
VERY LIGHT SAND INSIDE OF BRAKE BELL. INSTALL BRAKE BELL CAREFULLY.
WAITED TO RECONNECT DRIVE SHAFT TO ALLOW TEST ADJUSTMENT OF FINISHED MECHANICAL BRAKE RELEASE AND APPLIED STATUS. sorry, still trying to learn to post photo

[loreepeter]

the posts I have sent describes the entire removal of the hyd auto park system.
this is not done 'on the road', or to be able to move a moho in an emergency.


in first post:Will install electric reminder to Apply. And release.

in a reply post:pulling drive line to remove brake........NO, this is in my post describing the entire removal of system and NOT to be done 'on the road'
sorry, if you thought otherwise.

[loreepeter]

one more try to post photo
if this works it is the original install from the factory.

the brake shoes were replaced with exact size as mentioned in previous post. note the clean area of the brake bell...care not to touch.

[Bella123]

Excellent information, can't thank you enough for the description and the photo. Also found oldusedbear excellent Web site rvautopark.com with the trouble shooting and complete brake adjust process.
Thanks again for your expertise and sharing it, new shoes for Bella the bus, a spare rgs switch and a cable cutter and chocks for the emergency fix this trip.

[Airstream12557]

Bella123, do you have the parts number for the spare brake cable you ordered?

Sam

[92landyacht]

Does anyone have an alternate part number or car application for the parking brake shoes? Would be nice if there's no Napa near by.

[Bella123]

10-594, cable, fits the brakes on my bus, 10-975. I now have a hook type wire cutter in the tool kit too.

Robert

[Airstream12557]

Thanks, Robert!

Sam (now carrying two RGSs in my MH)

[loreepeter]

shoes are standard, available at oreilly, auto zone, carquest, advance, napa.
after inspection of original revealed excellent condition of all related parts of brake shoes we decided to install brand new shoes anyway. little labor and only $25 provided 'brand new' driveshaft mechanism. note the adjust wheel is at the top with access of snap in/out cover. our goal was to slide brake bell over shoes without any force. we then pulled on cable to center shoes. removed bell and expanded reach till we could still slide bell on without force. took a few tries. we knew we could adjust shoes using wheel if needed. with bell installed the brake cable travel was tested. we had between 1 1/4 inch to slightly over 1 for full release to total application.

the brake cable from the 'backing plate' was reinstalled to the cable relay mechanism.
the cable from the cable relay that had come from the actuator was relocated to the left front of the engine [not near 'hot stuff']. dog cover removed for this chore.



we then removed the hyd pump under the hood. electric, hyd lines and entire pump.
the hyd lines were blown out catching a little fluid at the other end. the bolts holding the pump were a little difficult as the 'heads' rotated when loose. however, with patience we located the heads and held them to remove the nuts. heavy, nice to get the pump out!

[Bella123]

When you take the drive line off, and then the center bolt to get the drum off, does that mean that there is anything in the transmission you are taking apart? Or are you stopping before you affect seals, ATF, etc.
Thanks!

Robert

[loreepeter]

no, nothing in the trans. you can find a photo of the drum for sale at various web sites. cost is up to 400 or 500. our drum was mint. by carefully pulling the brake drum off and not getting any dust/dirt on the one seal you can see in my photo. we considered very lightly lubing the seal but decided it was not that important. kept all contact areas clean when reinstalling drum. think we just removed it once or twice for checking shoe centering. no fluid present. I believe the seal is just to prevent dust from entering spline area.....with the drum installed [tight] ....good as new. [our opinion....]