I have an 85 300TD and it needed a good seal & pad replacement and cleanup. I managed to get out the pistons and clean everything all up and get the new seals in and seat the pistons back in. But now I cant get the new dust covers back on.

I bought FTE Caliper repair kits for ATE rear calipers from Bimmerspecialist online. The seals went in fine but the dust covers have a problem getting fully seated on all the way around the outer groove of the piston housing.

Its as if its almost on but as you work your fingers around to the other side where its sticking out a bit, and push down, the other side pops up again. Its as if the metal ring inside the rubber is a touch too small.

Is there something that should be done to prep it? I already made some holes trying to press down on the rubber ring having the metal cookie-cut the rubber from underneath with the pressure of a metal screwdriver...(bad Idea) What a drag. For a couple pieces of rubber it cost me $20, per side.
Any Ideas of what the problem may be?
Thanks!
michael

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Anybody know anything about this?
I was wondering if there existed a type of sealant that can repair the small cuts made in the dust covers when i tried to force them on with a screwdriver unsuccessfully?
Thanks

Clean well. Superglue.

__________________
1979 240D Caledonia Green/cream gone
1982 240D stick Ivory/Palimino
1999 E300D White/grey

I think you need to hook one side on and stretch them over, I don't think you can push them on. I remember that I had trouble with the rear dust covers. I think the problem was getting something between the wall of the caliper and under the rubber in order to stretch it.

Maybe try something like a small Allen key when there's slack.

For rubber repair, you could try one of the various GOO products in the adhesives aisle in the big box stores. But in your climate and road conditions, maybe another $20 for two more gaskets might be prudent, assuming you didn't cut more than two of the covers. Keeping water out will protect the piston. The rubber may be coated with light powder or something that may keep the adhesive from sticking.

Agreed.

It's quite a difficult and tedious process that is better accomplished with three hands. The boot must start down on the caliper on one side and then two "hooks", preferably made from wood, must work on opposite sides to pull the boot around the lip of the caliper, simultaneously, so the original position is not lost.

I don't rebuild calipers anymore...........the aggravation is not worth the savings of $40.

OK, So it sounds like the metal ring inside the rubber is meant to have some stretch-ability. There seem to be small teeth like tabs that protrude out and upwards from the metal ring inside (copper looking material) like a flange to keep it from slipping upwards. It seems to be these perhaps that are preventing an easy slip on. But I guess it just persistence and learning the hard way.


I have a hard time convincing myself any adhesive will actually stand up to the rgors of a brake caliper. Knowing how hot they may get and the conditions they may go through. Its just such a drag to have to order a new set in. its like literally throwing $20 out the window for a small little mistake. The holes arent terribly big but of course it just would feel much better knowing they are sealed well and should last a while.