A Magnet Mystery

[Raz]

A couple weeks ago I wired our new tow vehicle. When I plugged it in to test things out I found I had a brake problem. When energized only one side would hum. I disconnected the tow vehicle and using the breakaway switch I tested each side by jacking up the wheel and spinning it. I discovered the passenger side brake was not working. I disassembled the brake and found the wires entering the magnet were sheared. I replaced the magnet and the brake once again is working but I can't figure out how the wires could have been cut. Any thoughts? Raz

[mcbrew]

Originally Posted by P. Raz

A couple weeks ago I wired our new tow vehicle. When I plugged it in to test things out I found I had a brake problem. When energized only one side would hum. I disconnected the tow vehicle and using the breakaway switch I tested each side by jacking up the wheel and spinning it. I discovered the passenger side brake was not working. I disassembled the brake and found the wires entering the magnet were sheared. I replaced the magnet and the brake once again is working but I can't figure out how the wires could have been cut. Any thoughts? Raz

Cut brake line? Has anyone taken out a life insurance policy on you recently?

[Raz]

Originally Posted by mcbrew

Cut brake line? Has anyone taken out a life insurance policy on you recently?

Now there's a thought. Nah, she can't back up the trailer.

[Darwin Maring]

The easy way to test:
Hold a compass next to the hub while someone else steps on the brakes and if the coil (Magnet) is energized the compass needle will move then do the same for the other wheel(s).

[Darwin Maring]

The magnet when energized pulls to the hub and rubs on it and then moves in the direction the wheel is turning thus applying the brakes. When you de-energize the springs in the brake assembly pull the magnet back to it's normal position so I expect the back and forth movement simply wore the connection to the breaking point.

[Raz]

The other side failed in the same manner. This time I looked things over carefully before I diassembled anything and noticed the retainer clip that holds the magnet to the brake arm was missing. What I thing happened is the clip rusted off allowing the magnet to flop around resulting in broken wires right where they enter the magnet. In the future I will check the condition of the clips at every grease interval. Raz

[Alf S.]

Hi: P. Raz... Sounds like "The weakest link" theory at work here!!!
Alf S. North shore of Lake Erie

[Thomas G.]

You didn't solder those wires on did you?

[Raz]

Originally Posted by Thomas G.

You didn't solder those wires on did you?

Yup. Don't tell anyone , I used lead tin solder too.