Procedure for Testing Electric Brake Magnets

Question:

How to test magnet on electric brakes.

asked by: Marcel

Expert Reply:

First, do a visual inspection. You should make sure that the front of the magnet is not worn to the point where the interior copper windings are visible. Also, check the armature surface (inside rear of brake drum where magnet rides) is free of grooves and replace if necessary.

Next, you can test the voltage at the magnet while the brakes are actuated. Turn your brake controller up to its maximum gain, and have a helper apply the manual override switch. If you use a circuit tester like part # PTW2993 on one of the wires feeding the magnet, you should get pretty close to 12 volts. You will lose a bit of voltage, but it should be 11 volts or better.

Then, you can use a multimeter like # PT89ZR to test the individual magnets. I will link you to an FAQ article that lists the exact procedure testing a magnet for amperage, shorts and resistance.

expert reply by: Mike L