Originally Posted by Mr. D
Hi everyone, I am continuing the process of restoration and maintenance on my '88 345. I hope to have it ready for retirement in the next year or so. I need to know if the electric brakes on my tag can be completely rebuilt from scratch (I have not opened the hub but I think it could be ugly) or if the entire axle can be replaced if necessary and where? Currently the brakes are disconnected and the last owner did so to avoid continuing lock up problem. It performs great with out them but I was thinking that in the mountains it would be a nice feature to have in place. Also, from the rear my tag wheels appear to be slightly sloped in at the top. I hope someone can help, Mr. D.
I have a 1989 370, and I suspect our tags are the same. They are the same axle as the travel trailer uses, rated at either 3,000 lbs., or 3,500 lbs. (can't remember for sure, but just saw this in my manual the other day) To answer your first question, the answer is yes. Your brakes are just like almost every trailer brake in the industry. They use standard magnets, actuator arms, shoes and hubs. Any good trailer supply could provide these for you. Have you considered that the problem is the controller? It's mounted up high under your dash on the left side of the steering column, if it's like mine. Doesn't look like a dash mounted trailer controller - just a black box with the brake wiring coming out, and a single adjusting screw. My suspicion is that the locking up was caused by a controller either out of adjustment, or just plain shot. If you have the manuals for your coach, there's a somewhat sketchy description of the controller in there. If your controller proves to be the problem, one solution would be to trash it, and use a standard dash mounted one like is used on trailer brakes. That way you could adjust the braking to match your coach's hydraulic brakes. You definitely should pull your tag hubs and inspect the magnets, shoes, hubs, armatures, etc. to be sure all the parts are wearing evenly.
Not exactly sure what you mean by your wheels being slight sloped in at the top, but the tag axle on Airstreams are slightly bowed up in the center. If you look from the rear of the coach it makes the wheels appear somewhat tilted, but they shouldn't actually be. You can check that, of course, by looking at the tire tread wear. If they're wearing badly on the outside of the tread (assuming a tilt to the outside at the top) then you may have a real alignment problem, but I would check the tread wear first.
Since you are saying the brakes were locking up, that would most likely mean too much electricity getting to the magnets - which would tend to incriminate the controller for sending too much juice to the tags. Any good trailer maintenance manual would have a good section on brake maintenance, with good illustrations to show you exactly how to service the parts. Your tags are just that - trailer brakes.
Hope this helps a little.