no brakes

[danemayer]

Brakes were working pretty well after adjustment, but in order to fix the out-of-round drum problem, Dexter decided that the drums, brake assemblies, bearings and seals should all be changed out. They wanted to examine the parts for failure analysis.

The truck/rv repair shop they sent us to just spent 6 hours installing the new parts. The result is that the brakes are weak again. Even on 10, the controller will barely stop the rig from rolling at an idle. It won't lock the wheels when throttle is applied lightly (no pull test possible). They tested by pulling the breakaway cable to isolate the brakes from the truck's controller - no help. They checked voltage at the brakes and got 12V. With wheels off the ground, each wheel is adjusted to scrape lightly, and when the controller is pressed while the wheel spins, it instantly stops. They took the drums off again and cleaned all the new parts and checked all parts carefully. Everything looks good. At one point, they adjusted the brakes so tightly that the rig would barely move when idling, but still would not lock the brakes and was still very weak stopping.

But at the end of the 6 hours, it's not working right. The mechanics are stumped. I'll be calling Dexter again tomorrow morning to see where we go from here.

If anyone has any ideas, please feel free to jump in.

 

[danemayer]

Brakes are now working

Talked to the Dexter engineer this morning. He asked us to do a break-in of the shoes. Drive 50 miles, applying the brake controller alone about once per mile to slow down from 40 to 20mph. We did that and then drove another 8 miles braking normally. Braking is much improved and feels about normal in a hard stop on a slight downhill. The brakes also held for a pull test. The controller is set at 7.5 versus my previous normal setting of 5.5 to 6.0. But I suspect we may get additional improvement on the next leg of our trip. At any rate, I now feel safe to travel on interstates.

Am also starting a new thread to share this info and some other stuff I found out.

 

[chief190]

Hello
I hope my saga will end soon. I just got a call from dealer and they said dexter is paying for everything. I have not picked up my trailer yet as it is fair time in calistoga and as a fair director I'm a little busy. Will tow it home next saturday the 9th and will see how a heartland should stop. I have more than a little expierence with brakes and am sure I will need to properly adjust brakes myself when this is all done. A common mistake that most people even techs makes is to adjust brakes to tight. As you already know the front or primary shoe has to move roatationally to apply the secondary shoe that is doing the majority of the braking. If you looked at the shoes the front has less friction material that the rear this is by design. by overtightening them the mechanical mechnism it can not properly rotate and apply the secondary shoes. hope this helps you understand drum brakes a little better.