brake magnets

[Mike S.]

Another question please. Does anyone know how thick the magnets are when new? Mine measure @.720 inches. If they were .750 when new, I won't worry. If they were 1.00 when new, might be time to worry. Thanks for your time. Mike

[overlander63]

It depends on which magnets, what size brakes, how old the magnets are.

[Mike S.]

Axles were made in sept 2013, 12 x 2 brakes. Axles are 3800# capacity.
Thanks, Mike

[HowieE]

Generally there small holes on the face of the magnet. When any area of those holes disappear, they don't always ware evenly, it is time to replace. If left beyond that point you run the risk of cutting into the coil windings.

[carl2591]

Just did magnet replaced this weekend as well.. did not measure the new ones but I can drop by the place we get them Agri Supply and measure the thickness..

I will post some pic of the ones I took out.

you can see coils on a couple of them. Was an all day deal but it gave me chance to repack bearings, check hubs and smooth out the magnet side of hub, and rotate tires back to front.

Two picture show old units and ones shows a new one.

PS tried to call tractor supply and spoke with one of the girls and she was not able to find replacement magnets there and could not find them on the website either.

[Al and Missy]

Place a straightedge ruler edge on the magnet in several orientations (lengthwise, crosswise, diagonally, etc. If there are gaps, i.e. unevenly worn edges like yours, they should be replaced. If wires showing, definitely should be replaced.

If one magnet on an axle is changed, the other should be, as well.

Also, check the magnet surface on the flat inside of the drum. If badly scored, the drum should be turned or replaced. Not many places can turn brake drums anymore. The best bet is a truck repair shop. Most can turn the round shoe surface, only a few can turn the flat side. If one drum on an axle is turned/changed, the other drum should be as well.

http://www.dexteraxle.com/docs/defau...s.pdf?sfvrsn=2


Al

[carl2591]

Yeah did that .. change all the magnets all of which showed different types of year but all were past the holes in the maganets.

The drums inner surface was not bad, some had a bit of scoring so I took emery cloth and sanded to smooth and rough up the surface.

Yesterday I was able to take the trailer on a drive,over to Discount tire to get a complete 4 wheel balance, and along the way was engaging the trailer brakes to burnish and break in the new magnets.

Since I was in a bit of traffice and not able to do the 40 mph to 20 mph deal I wouild get in "clean air" accelerate and pull the trailer brake handle holding it on for 5 to 6 seconds while mashing the gas and release and let it cool for a min or so and do again.. I was able to do this about 4 times on the way there and got tires balanced.

coming back I noticed the brakes now were 1000% better to where i had to back down brake gain to keep from snatching the truck with trailer brakes.

MAN what a difference for sure.. this all started due to a hot hub after we went to pickup unit at storage area. All is good now.

[carl2591]

size of magnet: 3.16" x 2.02" W x 0.95" D

this is from a website that sell magnets for a lot of money.. Agri Supply price is 6.99 each.. most places are like 12 or more each plus shipping.