Electric trailer brakes help.

Discussion in 'Mechanic and Repair' started by o-so-n-so, Jul 28, 2006.

  1. o-so-n-so

    o-so-n-so LawnSite Bronze Member
    from Alabama
    Messages: 1,218

    Im having trouble with my electric trailer brakes. I removed the drums today to see how these things are set up. It looks like a standard set of brakes except for the electro magnetic brake actuator. My problem was gradual, my brakes just got worse and worse until they just stop working. I adjusted them out today and checked the liner and its all ok. The only thing left is the electro mag part. Is this most likely my problem? I can hear the brakes try to work but they just don't do anything. My controller inside the truck seems to be working ok as well. What do I need to do next?

    Thanks for the help.............SC
  2. ed2hess

    ed2hess LawnSite Fanatic
    Messages: 14,588

    Put a rubber band on the controller to hold it in the actuated position. Then you can jack up each wheel and determine if they are grabbing or not. In fact you should be able to hear them hum it they are working. If they are making the humming sound and not working I would look at lubing all the pivot for the magnet arm. Usually they either "hum" and work or are dead and make no noise. Darn brakes cause more problems than anything else I am constantly fighting them. It is important to have a good ground as well as the 12 volts. I ran a gnd line from the connector all the way back on mine to be sure I had good gnd.
  3. oldrustycars

    oldrustycars LawnSite Senior Member
    Messages: 301

    everything ed2hess said is correct. be sure you know how to adjust your brake controller as well. be sure the magnets are clean, as well as the surface the magnet grabs to. if a wrench will stick to the energized magnet, its good. i adjust brakes so i get a light drag all the way through a rotation. electric brakes are simple, really. they are your friend. take the time to understand them, and it will come easily. theres only so much that can go wrong with them.
  4. notoriousDUG

    notoriousDUG LawnSite Member
    Messages: 70

    I agree with everythign said above.

    Check the wiring VERY closely, it can causemore problems then you suspect. Also check grounds very good. I find it hard to belive that ALL of your magnets went bad together.

    You can change the magnets by themselves but unless the drum looks like new and is very flat inside two I like to change them as well.

    Of course 90% of the time if I am experiancing a brake issue and the brake is not very close to new I replace the entire thing and the drum with it. While it seems spendy it is worth it in the long run to know you ar enot goign to have any issues there, brakes are oneplace you should never cheap out.
  5. o-so-n-so

    o-so-n-so LawnSite Bronze Member
    from Alabama
    Messages: 1,218

    When I removed the drum on left rear axle, the drum surface (where the magnet grabs) looked pretty rough. The seal on the drum was bad so I removed old seal and bearing, cleaned and repacked bearings, installed new seal and adjusted the brake shoes. I done a visual on all moving parts and it seemed to be moving freely. I buckled it all back up and checked it. The brakes were still no good. After reading you guys posts, I am better prepared to go back in and resolve my braking problems. I think I will need a new drum on that one axle. The axle is a 5200 lb axle. Any ideas as to where to buy replacement parts? Its not a dexter axle.

    Oh, The electric wires only go to one side of the trailer and I bought the trailer new. Do you think the other side has all new inners thats never been in use? No one has ever worked on this trailer until now and its about 4 years old.

    I think I will put the trailer on jack stands, remove all the wheels and drums and start replacing stuff. (reason) I almost lost it (tractor on trailer) in the rain Saturday.

    Your posts has been a great help.
  6. wriken

    wriken LawnSite Silver Member
    Messages: 2,154

    Are they 12"x 2" brakes if so i just got some from http://shop.easternmarine.com/index.cfm
    about the cheapest I found.
  7. fixer67

    fixer67 LawnSite Silver Member
    Messages: 2,098

    Not sure if any one has said this but the controller ramps up the volts from 0 to 12 volts and you push the brake pedal down. The farther down the pedal goes the higher the voltage goes. To test the controller unplug the trailer cable and get you a battery ( car or riding mower) and run 12 volts straight to the brakes. Now try to pull the trailer. If the wheel still roll you have brake problems. If the wheel are loaded and drag then the controller is the problem. This is a real quick and sure fire way to rule out the controller as the problem.
  8. notoriousDUG

    notoriousDUG LawnSite Member
    Messages: 70

    The wires only go to one side!?

    If that is true it is scary any manufacture let one out like that.

    Sometimes they run them inside of suport beams or across the axles.
  9. o-so-n-so

    o-so-n-so LawnSite Bronze Member
    from Alabama
    Messages: 1,218

    No cross over at all.......I can see the magnet wires coming out the backing plate and there not attached to anything. I'll investigate the situation further when i get back to the brakes. Might have to wait on a rainy day.

    I believe my controller is constant with adjustable controls on the unit itself. It has 2 adjustments, one for inertia and one for braking power (volts to the brakes)....I think thats right.:confused:

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