Odd Repetitive Trouble with my Alpenlite brakes

[howardwheeler]

I have Neverlube Dexter hubs that came with the fifthwheel that are rated at 8000 lbs per axle, though the Alpenlite trailer literature says I only have 7000 lbs axles. I don't know why that is, and it's probably irrelevant. I'm glad I have big brakes because it's a heavy 16000 lbs trailer. Anyway I started losing my brakes on my last trip of around 600 miles. Scary! Upon checking them back home, one magnet was no good, drawing no amps, but the odd thing is that my passenger side front brakes had no lining left at all. All other hubs had great lining. The oddity is that three years ago on a trip to the Canadian Rockies (if you've never been, go!) my brake on the same hub locked up. We dismantled it in the Banff campground (fun) and discovered that the brake lining had come loose from their metal backing and just jammed the whole hub. This is the same hub that once again has lost all the lining. I don't know if they fell off again (we replace the entire backing assembly with a new one we found in Calgary), or if they just wore down, but they were gone and it was metal to metal. What's happening on that hub? Tires all wear evenly, but for some reason that hub gives out. This time, we also found a questionable ground connection where the brake wires first connect with the wires that then go to each brake. It seemed corroded. We are redoing each wiring connection, but we don't really know if any were really bad. So, does anyone have an idea about why that hub does this while all the other brake lings look great? The hubs are 12.25x3.375.

[larry_barnhart]

we are still on our original brakes. I would have thought we should have worn them out but still good.
chevman

[restlesswind]

the post by Chris leads me to believe that a wire going to that wheel is shorting to ground (probably intermittently).My guess is that it's inside the hollow axle shaft. A good reason to re-route the wiring.

I have the same setup on my fiver.7k axles 8k brakes w/never-lube bearings.
The trailer weighs right at 15k the braking is excellent.I also have a
MaxBrake controller and PacBrake EB. Over 65K miles towing and the brake shoes are less than 25% worn.

[Me_Again]

We have to understand olms law here! If that one magnet was shorted out with very low resistance most of the current would go to ground at that brake with hardly any at the other three.

Let's say three magnets are at 4 olms each and one at 1 olm. Current takes the path of least resistance with most going to the 1 olm one.

I would be checking the resistance of each magnet when you take it apart to solve the mystery. Keep track of each magnets wheel position. Measure wire to wire and each wire to metal body of the magnets. Build a little chart and see what you read with the meter.

Everyone should have a good multi meter and learn how to use it. Chris

[Cummins12V98]

howardwheeler wrote:
We got everything back together, and the braking is back to normal, which is adequate but wish it had more stopping power. Amps are good. But I'm still interested in the dynamics of the four brakes. Is it possible that when one magnet goes out that the pressure on braking on the opposite side of the axle increases? Does the front axle take more of the brake load? It just gets me that all the other brake shoes have lots of life (they're big shoes), but this one brake has failed twice. I just don't know about the differing loads on multiple axle brakes. Any experts?

Do what I suggested earlier. Install a disk brake kit. My Dad's axles were the same as yours. He finally got sick of dealing with the electric brakes.

[Old-Biscuit]

howardwheeler wrote:
We got everything back together, and the braking is back to normal, which is adequate but wish it had more stopping power. Amps are good. But I'm still interested in the dynamics of the four brakes. Is it possible that when one magnet goes out that the pressure on braking on the opposite side of the axle increases? Does the front axle take more of the brake load? It just gets me that all the other brake shoes have lots of life (they're big shoes), but this one brake has failed twice. I just don't know about the differing loads on multiple axle brakes. Any experts?

Each brake operates independently based on voltage/amps to magnet, contact surface, brake shoe lining and adjustment.
One brake going out doesn't increase/decrease other brakes operation/function just the overall stopping power of rig.
Weight on each wheel will affect that wheels braking ability.

[rhagfo]

B.O. Plenty wrote:
Junk all of the complete brake assemblies and start all over from the backing plates out. They only cost around $50-75 per wheel. Then scrap all the wiring and replace it with new. You have an old trailer, why waste a buch of time on it when you can just replace it all for not much money..

B.O.

X2 to this,
This is my late winter early spring project! While my brake assemblies are in good shape, I plan on replacing all the brake wiring, with heaver gauge and all soldered connections.
I will be doing this and adding a real set of backup lights to the 5er.

[howardwheeler]

We got everything back together, and the braking is back to normal, which is adequate but wish it had more stopping power. Amps are good. But I'm still interested in the dynamics of the four brakes. Is it possible that when one magnet goes out that the pressure on braking on the opposite side of the axle increases? Does the front axle take more of the brake load? It just gets me that all the other brake shoes have lots of life (they're big shoes), but this one brake has failed twice. I just don't know about the differing loads on multiple axle brakes. Any experts?

[restlesswind]

According to Dexter,the 8,000 lbs per axle should pull 3 amps on each magnet.
When all are working properly there should be 12 amp draw.I could be a little
more or less.(Mine draw 13 amps)
Possibly a short at the magnet on the wheel with the bad brake.Replacing the
wiring may be the best way to go.
You might do away with the wires in the axle tube,that is a good place for trouble to develop.

[Cummins12V98]

Skip the electric brakes and go with a disk brake kit from Kodiak. My Dad and I did so on his 96 HH Premier this summer and he is thrilled with the brake performance. His RV is heavy also. Well worth the money. Easy install.

[Veebyes]

Sounds like I may have similar issues with my 2007 Alpenlite brakes. Also self adjusting. I am one for doing touch checks at rest stops & any stops when driving the mountains. Rear axel drums, both sides, get warmer from braking. Bearing temps similar all round during extended highway running.

Planning to replace whole plates, magnets & shoes all round though I suspect front ones will be perfectly good. Will clean them up & keep as spares. Will also get a couple spare bearings.

Planning another Alaska trip & it is nice to at least have vital spares onboard eliminating a potential shipping wait or absurd amount for express shipping up there.

[donn0128]

howardwheeler wrote:
I wish my assemblies were so cheap but they are close to two hundred fifty dollars a piece. They are very large. We are redoing all the wiring and did check voltage at each magnet. That's how we found the bad one. The bad magnet was on the same axle as the hub that eats brake linings. I did just begin to wonder that if that magnet has been bad four years could that cause the first failure?

Where are you getting that price quoted? from a dealership.
If they are really that price my first suggestion is to dump the antiquated brake design and go for disk brakes. Total cost is only around 2000 dollars plus some labor. If your the least mechanically inclined it is a DIY job. And well worth the time and effort.

[Old-Biscuit]

howardwheeler wrote:
My hubs have self adjusting brakes. We did though readjust them when we had the failure a few years ago.

Self adjusters......
Then is sounds like the one that over wears is over-adjusting (or the others are not adjusting when you brake)

That and along with low voltage/amps on magnets.
Magnets have to grab contact surface in order to engage primary shoe which then rotates and applies secondary shoe. This action also adjusts shoes via cable/lever moving and turning star wheel
If surface is rusted or low voltage/amps to magnets they can't grab

[howardwheeler]

My hubs have self adjusting brakes. We did though readjust them when we had the failure a few years ago.

[the_bear_II]

Maybe that one brake has been doing all of the work, due to incorrect adjustment, wiring problems on the other wheels.