How strong are trailer brake magnets supposed to be?

[4570Man]

I’ve spent the better part of the day troubleshooting my trailer brakes to no avail. As a last ditch effort I hooked the magnet to a battery charger and stuck it to a piece of 1/4 thick steel and I could drag it off with one hand. I think it should be way stronger. The magnets don’t appear to have much wear. It’s still 1” thick. It’s on a 10k axel.

 

[TMGT]

Put a meter on the magnet and check the resistance across the magnet leads, there is a spec. based on what size magnet/brakes you have.

The magnet isnt super strong, it relies partly on the friction material on the magnet and most trailer brakes are self energizing so it doesn't take a lot of force to apply them.

 

[tookielee]

I had a Ram pickup with a factory in dash brake controller, even on the highest setting, had very little trailer braking.
Same trailer I had used for years with aftermarket controller with no issues. Just for fun, hooked it up to the Ford
with factory brake controller, and it could once again lock up the tires when the trailer was empty.
Moral is, may not be the brakes, may be controller

 

[cat fever]

Or it could be the brakes need to be adjusted.

My understanding is; jack wheel off the ground, tighten adjuster until you can't spin the tire, loosen adjuster until you can spin the tire. Done

 

[ruffdog]

Good video on how brakes work.

 

[4570Man]

I’ve already adjusted the pads. I’ve already hooked another trailer on the truck. I’ve already hooked a battery direct wired to the brakes.

 

[TractorNH]

I had electric brakes on a 9 ton tri-axle trailer and with a 12k machine on the trailer I could lock up the brakes at 35 mph if I didn't adjust the gain on the controller correctly. It sounds like your magnets aren't working correctly.

 

[TMGT]

What is the amp draw on the system and individual magnets? What's the ohms reading across the wires for the magnet? That will tell you whether its electrical or a mechanical issue. Here's a good writup on testing trailer brake magnets.
Testing Trailer Brake Magnets for Proper Function | etrailer.com

I’ve already adjusted the pads. I’ve already hooked another trailer on the truck. I’ve already hooked a battery direct wired to the brakes.

 

[ruffdog]

Also, the wires tend to break off right at the magnets from movement bending the wires. Maybe the wires are partially broke so they are not using as much amps as they should?

 

[fried1765]

I had electric brakes on a 9 ton tri-axle trailer and with a 12k machine on the trailer I could lock up the brakes at 35 mph if I didn't adjust the gain on the controller correctly. It sounds like your magnets aren't working correctly.

Agreed!
With my trailer gross at 12K I can set the electric brakes to bring my GMC2500 Suburban to a normal (without trailer type normal) stop.