Trailer, electric brake problem

[ns_in_tex]

I have a tandem axle trailer with electric brakes on all wheels.
One wheel wants to act as if after applying the brakes, it now has a permanant magnet & does not want to release, even when the wheel is rotated in the reverse direction the magnet will just continue to hang to the drum.

I have tried:
1. Disconnecting the wires after this happens.

2. Reaching through the back side of the hub with 2 screwdrivers to pull the magnet away from the drum.

3. Pulling the drum to see if the magnet would pull on a screwdriver, No.

4. Pulling the drum on the other side to see if I could see any differnence, NO.

Has anyone had a similar problem & could advise me what to look for?

With the wheel off the ground, brake applied, wires then disconnected, the wheel will still stay locked, both directions.
After several hard reversing of directions, it will brake loose & start spinning.

Any advise would be appreciated.

 

[Highbeam]

Something must be assemebled wrong or not moving well. Lube the typical seize points and be sure that the parts all look and move like the adjacent wheel. There just isn't much to go wrong.

 

[Egon]

Pull the brake drum off and check it out. If need be the whole brake assembly can be replaced almost as cheaply as rebuilding.

Egon

 

[RobertN]

I had to make a repair to a trailer brake a while back. At our local trailer supply, it cost about $55 for an all new backing plate with all components installed.

I cut the wires from the old backing plate, unbolted it, bolted the new on on, and put the drum and wheel on. Worked like new. Oh, I reconnected the wires too /forums/images/graemlins/wink.gif

 

[Highbeam]

It is a bit of a pain to take the drum off for a look-see since the bearings hold the drum on but you don't have much choice.

 

[ns_in_tex]

Thanks Highbeam, Egon & Robertn for your suggestions.

Below is what we experienced.

Hope it might help someone from going through what I did.

In short (if you don't want to read it all) the electromagnet was retaining its magnetism, although when I pulled the hub & held a screwdrive up to it, I thought it was OK.

THE LONG STORY.

I probably would never have known anything was wrong, except I had been doing a little maintainence on the trailer and had taken it for a spin. On returning, I decided to use a infrared thermometer on the brake drums to see if they were even temperatures. Three were a little over 100 degrees & one was 375 degrees.

These are over 30 year old mobile home axles which I had installed 8x6-1/2 brake hubs on so I could use the tires off my one ton truck.

With the trailer jacked up & rolling the wheel by hand, then applying the brake, I could tell it was not releasing properly. The magnet would follow the drum when turned to the rear until the brake caught in reverse.

I pulled the drum today (maybe the upteenth time) and the screwdrive still did not seem to pull to the magnet when the drum was first pulled.

I energized the magnet & put two lug nuts on it. Removed the current & the lug nuts had to be pulled off after one hour.

I then got another magnet, energized then put lug nuts on it. They fell off immediately when deenergized. Put this new magnet on the trailer & the brakes return to home position as soon as the current is removed. You can hear the click as the magnet fall to the bottom when current is removed.

I found that two of the other wheels were not as bad as this one, but do not release as well as the other two do (do not hear the click of the magnet falling to bottom position when current removed), so I will be getting two more new magnets.

That all folks,
Have a good one

 

[Egon]

Good show.

several years ago when I rebuit the trailer brakes the pieces all fell on the ground when the first drum came off. Before doing anything else I went and got the complete rebuilt kits for all four wheels.

Egon

 

[Highbeam]

Thanks for following up. I learned from your solution and would not have thought the magnet would magicly stay energized.

 

[TonyV]

Wow....when I first read of your problem I thought for sure that there must be some kind of mechanical hangup occuring. The materials that make up the electro-magnets should under no circumstances retain magnetism. This property of magnets is referred to (oddly enough) as retentivity /forums/images/graemlins/wink.gif. To me, this is a flaw in the manufacturing of these brakes and could lead to dire consequences. I would definitely get in touch with the company that produced these things and try to get them to replace the brakes, given the circumstances. If I didn't get any satisfaction with them, then I'd get in touch with consumer advocacy groups and sound an alert as to this dangerous product. By nature of the application, that company should have used extremely 'low retentivity' materials in making these brakes, and perhaps by now they have, especially if others have had the same problems.
In any event, I'm glad you found out about the problem the easy way.

...Tony

 

[ns_in_tex]

Hi Tony,

I really don't think I am due any recourse. I built this gooseneck trailer about 1974 out of the scrap/junk pile at the mobile home mfg I worked for. Back then we used it to haul 2 tractors on (at the same time) along with a John Deere square baler hitched on behind. I had a teen age son then & we did a little custom hay baling in addition to the 32 acre coastal hay meadow we did for ourselves.

It has hauled a fair amount of hay, 8 round bales per trip.

I just found out while changing to truck style hubs recently, the front axle had John Blue stamped on the hub and the rear was a Fayette. I don't remember ever hearing of a John Blue axle. Three of the magnets were one style and one was another style(mixed on the same axle). I suspose we must have taken a good end off of 2 junkers & made one.

This trailer has served me well, I can not complain.