Electric Brake Issue

I must admit I was taken aback when I first worked on my TT brakes. My first thought was "what a Rube Goldberg concoction." An electro-magnet riding against the brake drum pulling on the brake shoe lever. Still I had to admit I had nothing better to offer.

My TT was 3 years old and lightly used when I bought it. 2 1/2 years and 21,000 miles later I can tell you that the magnets are deeply scored and very dirty. I have had to replace two that had worn through to the copper.

When I had the bearings packed I was told they "looked" okay. Now I look for myself.

I do not know that there is much that can be gone except to periodically replace the magnets and drums and to adjust them as needed.

I was curious how often others service their TT brakes.

trailer brakes are fine mechanically and adjusted carefully, I just did it. plenty of pad material left, free movement of all parts, freshly lubed with brake lube on the arms and shoe/backingplate contact areas.

we still have the old trailer, brakes are fine on it(full lockup using the manual push button.

so it pretty well comes down to electrical on the new trailer(12 yr old)

i'll check the resistance between the brake pin on the plug and ground

i'll jack it up one side at a time and pull the breakaway switch

edit: I have 1.5 ohms between the brake contact and ground at the trailer plug. sounds about right for 4 coils in parallel

we took the trailer/truck for a short drive last night, very little braking action using the manual override button

with a voltmeter across the trailer battery, I read 12.4 volts then 12.2 with the breakaway pin pulled, so the brakes are "pulling" current from the battery

I also jacked up one side, pulled the breakaway pin and both wheels are locked solid

btw, it took a major effort to pull the breakaway pin, it should be pulled and lubed once in a while, much easier to pull out now!!

How old/mileage on current brake shoes?

When waas last time you pulled a drum and inspected brake components?

When was last time brakes were MANUALLY adjusted...and how was that done?


ALL the messing/fine tuning of a brake controller will NOT take care of a mechanical issue......brakes need to be clean/and properly adjusted PRIOR to setting up controller

Each of my brake magnets measures 2.8 ohms so each will draw about 4.25 amps or 17 amps for all four.

My controller only feeds as much current to the brakes as adjusted on the side knob, even in the manual mode.

I have never been able to lock up my brakes no matter what the controller setting on my current TT. I can lock them on my PUP and on another TT I towed but not on my current TT.

So there may be nothing wrong with your controller.

I can adjust the controller of neutral braking, but not lock up.

K Charles wrote:
4 magnets = 15 - 16 amps

That's a little high. More typical would be 3amps per magnet.

4 magnets = 15 - 16 amps

What kind of truck do you have.
When we got our 2012 Ram I wasn't aware I had to switch my controller over to heavy electric till after my first hook up and down my driveway when I almost didn't stop.

Once I switched it over it worked perfectly.
Most of the newer trucks are like that you have to tell it heavy or light electric or hydraulic brakes.