Electric Brake Question.

68 Suburban · 10-09-2002, 05:29 PM

Does the magnet ride along the inside of the drum? Does it actually contact the drum? Thanks

uwe · 10-09-2002, 05:36 PM

yes, when activated by the brake controller the magnet slides on the inside of the drum, which in turn drags the lever with the rotation of the drum, which in turn expands the brake shoes which in turn slows things down.
So, the magnet is actually a part that needs periodic inspection, sometimes replacement. The brake drum has a machined surface which the magent drags on when activated.

68 Suburban · 10-09-2002, 05:38 PM

Thanks for the info. How can you tell if a magnet needs to be replaced? Thanks

uwe · 10-09-2002, 05:48 PM

I have not had to replace mine, but i would look for a magnet that shows severe wear patterns, or grooves. Also, the magnets are supposed to be shaped like a small brick, some are oval, and should be replaced if they are worn out of shape. Out of shape would be uneven, like thinner on one side.
Hopefully another member will have a more scientific explanation. Of course you need to check the brake drums at the same time.
I would replace everything on the brake system if the magnets and shoes are worn.

Inland RV Center, In · 10-09-2002, 07:48 PM

Round magnets should be replaced when the "top" of the three screw heads start to wear. Should the magnets not be replaced at that time, and if the magnet is wearing unevenly, and they usually do, you will take the chance of going into the wire coil, which means an instant short in your brake system.
Typical all around mileage expectations for round magnets are for a single axle, about 15,000 miles. For tandem axle trailers about 18,000 to 20,000 miles. Shocks should be replaced at every other magnet replacement. Brake shoes on single axle trailers usually last about 40,000 miles, and on a tandem, about 50,000 to 60,000 miles. A bearing repack should be done once a year, or, every 10,000 miles, whichever comes first. Grease seals should be replaced at every bearing pack. Running gear should be balanced every 10,000 miles.

Andy
inlandrv.com
airstreamparts.com

68 Suburban · 10-11-2002, 01:47 AM

Andy, Shocks for an 1968 Avion T-22 Dual Axle trailer?

Inland RV Center, In · 10-11-2002, 10:10 AM

Not sure what Avion used back then. Give me the retracted and extended dimensions, and is it horizontal or vertical? I will check it out for you.

Andy
inlandrv.com
airstreamparts.com

68 Suburban · 10-11-2002, 10:14 AM

It is a smaller vertical shock. I will have to measure it today. It has stud mounting on both ends and no eye mounts.