Brakes have not been used in years

[lwebb]

If I can butt in and ask a question, My brakes haven't been used in years. Don't know how long. I have pulled power to each but not connected it. It is my understanding that one of the electrical connection is the ground and the other the power. I grounded one and put a continuity tester from that pole to the other and it says the other is grounded as well or shows continuity? Nothing is attached?
Does this make sense?
Help!

[Campaz]

The actual brake magnets don't have polarity or positive and negative. Hook the positive to any of the two wires and negative to the other, it doesn't matter, the magnets are actuated by the current going through them not the direction of the current.

[lwebb]

Thank. Rick, That makes sense now.

[lwebb]

OK I have power to the brakes and I tested the magnets with the hubs off and they work but when the hubs are on and I power them up, I don't hear anything? What does it refer to when a post says "remove the plug in the back plate, adjust the star wheel with the special brake tool" I'm afraid I don't know what a back plate is not to mention the star wheel. Is there a diagram of the mechanical parts of a magnetic brake?

[overlander63]

On your brakes, if you have never worked on brakes before, and don't know how to work on them, don't mess with them. Take the trailer to somebody that knows how to work on them, and watch them. Ask questions. Take notes. Once the other person takes the drums off, you can ask them what this or that part is, and how to adjust it or make sure it works.
If you do it wrong, you run the risk of not only having brakes that don't work, but possibly not being able to stop in an emergency, or having the brakes lock up while driving.

Now that you've been warned, if you're still with me, this is how trailer brakes operate, and how to adjust them:

When you step on the brake pedal, the brake controller sends power to the brake magnets, which are then attracted to the side of the brake drum, against a machined surface. Mechanical friction of the magnet moves a lever that goes from the magnet to a spreader bar between the brake shoes, at the top. The brake shoes then move outward against the drums, and mechanical friction slows the wheel. When you relese the brake pedal, the brake controller stops supplying power to the magnets, which release, and the brake shoes return to their normal resting position with the aid of return springs.
Adjust the brakes by spinning the star adjuster located on the metal plate behind the brake drum, this is the backing plate. You will see the brake magnet wires leading into the backing plate. The star adjuster can be spun by sticking an adjusting spoon (special tool) or a flathead screwdriver into the hole at the bottom of the backing plate. The hole is usually blocked with an oval rubber plug. The adjuster is positioned at a 90 degree angle to the wheels, so you would stick the tool in, and move it up or down to adjust the brake shoes. Adjust the brakes until the shoes drag, then reverse the adjustment a couple of turns.
The tire and wheel assembly will need to be off the ground to do this.

[Lumatic]

The backing plate is the large plate all the brake components are attached to. At the bottom or the backing plate is a slot that should, but may not have a rubber cover that pops out. Directly in front of the slot is a round wheely thing that looks like a cowboy spur attached to a threaded rod which adjusts the brake drums by pushing them outwards or drawing them inwards. There is a generic "brake adjusting tool" you can get at an auto parts or Wallyworld store. But you can also use a good size screwdriver.

The brakes are adjusted so there is a very slight drag on the hub. If you have never done it get someone to show you. Consider greasing the bearings while you have the drum off.

[lwebb]

Thanks guys.
I repacked the bearings and checked that the magnets worked. I'll take it to a trailer place Monday to have them adjust the brakes.