Autopark help...

[bford9]

I've read all the threads about the Rotten Green Switch, but I don't think that's my issue. I currently have NO park functionality at all on my 2002 Coachmen Pathfinder QB300 Workhorse 8.1L. I have the push/pull style yellow e-brake, which also does nothing at the moment. I'm able to drive my RV and I hear the autopark motor whine for a few seconds and then goes off, along with the autopark light. I got underneath and verified the actuator is actually moving freely when put into gear and back when it's placed into park, however when in park the RV keeps rolling. I'm assuming I need to replace the park brake shoes, but hoping someone could verify and provide some instruction about how to tackle this project. I called an fleet transmission place and they wanted $2,000 to do the job. I'd like to think it shouldn't require that type of expense and hopefully something I can tackle myself. Any thoughts / suggestions appreciated.

[astrnmrtom]

Hopefully, your shoes just need adjusting. Unless driven a distance with the brake on the shoes don't receive much, if any wear. I never replaced the shoes on mine but did adjust them and it isn't hard to do if you ever adjust drum brakes on a car. The drum has a slot for adjusting the shoes. You get the slot to the bottom and you can move the adjusting wheel with a flat bladed screw driver.

Here's a pdf that shows how to adjust the shoes, and offers insight as to how to remove the drum after getting the drive line out of the way. $2000 sure seems high to me. It doesn't look a whole lot more complicated than changing the shoes on a truck. Instead of pulling a wheel, you drop the driveshaft. Could be a little tricky getting the drum lose if it's been on there a while. Looks like it would be possible to attach a puller to the bolt holes of the U-joint yoke base on the drum.

Oh, be sure to block your wheels!

http://www.rvautopark.com/wp-content...king-brake.pdf

[swduns]

I've had two rigs with auto park. On both I preemptively over hauled the auto park system with upgraded parts from UltraRV.
One subsequently had an issue and it turned out I had to replace the drum. it had worn out/down over the years from prior owners driving with the break on.
On one I ordered the entire auto park brake back plate complete with shoes, springs, etc
This was one system I didn't want to have trouble with
I replaced actuator, cables, pressure switches, relay, brake back plate and ultimately the drum.
I would rather pay the money and do it right then never have to worry about it.
https://www.ultrarvproducts.com/
The guys are UltraRV can advise you as well on what they recommend you replace.

[Isaac-1]

Be careful adjusting the shoes, you don't want them to drag with the brake off, this can cause heat buildup resulting in a fire, more than one P32 coach has burned down due to someone mis-adjusting the APB shoes.

[bford9]

So I've been diagnosing my issues with someone on line and he thinks I may not have a brake drum issue, but rather a broken cable. Can anyone tell me how to remove the sheath to be able to access the cable and remove it?

[LETMGROW]

Unless I'm mistaken the actuator when retracted pulls the cable and releases the brake. If the cable was broken the brake would be applied.
Lynn

[bford9]

When put the RV into gear (neutral or drive) the actuator moves the cable out, which releases the brake. I see the actuator move, but nothing happens at the lever (doesn't move at all), which tells me the cable is most likely broken. Need some guidance in how to remove the cable from the actuator and the lever to diagnose it.

[edgray]

Originally Posted by bford9

When put the RV into gear (neutral or drive) the actuator moves the cable out, which releases the brake. I see the actuator move, but nothing happens at the lever (doesn't move at all), which tells me the cable is most likely broken. Need some guidance in how to remove the cable from the actuator and the lever to diagnose it.

I’m not sure what “lever” you are watching, and am certainly not an expert on how the J71 works, I find it hard to imagine why they expected a cable to PUSH anything as powerful as the spring that pulls the shoes into contact with the brake drum. The pump has to produce something like 1,500 PSI to overpower that spring.

[bford9]

I was able to unscrew the cable from the actuator and confirmed the cable IS NOT broken. I was able to pull/push it to the lever. I think I may just need to adjust the actuator tighter to pull the lever appropriately. Will try that later.

[LETMGROW]

At the top of this Workhorse forum page there is a link to a thread: "Workhorse Important Discussions"
Scroll down to discussion # 27 "Auto Park Brake"
Lots of reading but a wealth of information.
If you don't find the information you need call or E-Mail www.URVP.com and ask for Alan. He knows the system well and has the parts to repair it.
Lynn

[swduns]

Check out:
http://oemys-performance.com/media/autopark%20brake%20replacement.pdf

[swduns]

Another source:

http://www.wolfswords.com/motorhome/auto_parking_brake/PUMP%20MOTOR%20SWITCH..RGS...replacement.pdf

[swduns]

Another source:

https://www.nwtfc.com/wp-content/uploads/2020/04/Auto-Park-Brake-Library.pdf

[swduns]

Shift level specific info:

http://www.rvautopark.com/wp-content/uploads/2013/10/Diagnosing-and-repairing-Gear-Shift-Lever-Position-Switch.pdf