911 caliper rebuild-rear dustshield question

gchappel · 02-07-2002, 03:08 PM

Thanks to this board I have successfully rebuilt the front calipers for my 85 911- it was actually easy. Thanks!! The rears were easy as well- until I tried to put the rear dustshields on. These are the ones that have the metal ring molded into the rubber, unlike the fronts where the ring was a separate piece. Alright - is there a trick trap door or something? These things are not going on- at least not in 1 piece. I have the pistons out about 1/4-1/2". The shields are the correct ones, ordered from the correct place- thanks Pelican. I searched the archives and see others have found this difficult as well- there is talk of using baby food lids, crow bars, dynamite, etc. Anybody have a "trick" that works??
Thanks again
Gary

old_skul · 02-07-2002, 05:49 PM

I had the same problem as you. My solution was to take a peice of pipe, 2" diameter I think - essentially just large enough so that the inside diameter of the thing cleared the caliper body that the molded ring fits over. I cut a 1" section of the pipe and polished it down and smoothed the edges so that it wouldn't cut the rubber.

I put the "ring" on top of the dust boot and aligned it carefully, put a wood shim across the top, and used a c-clamp to mush the ring down - it popped right on. I still have that ring.

Brakes are like new, now. I just need new rotors!

Clark Griswald · Clark Griswald's Garage

That ring trick sounds great if you can make it work.

The difficulty I had with clamping this seal is a concern that the rubber part might be cut. In fact I tried clamping on one of my old ones just to test, and sure enough it cut.

Ultimately I got one on just by using my "kung fu grip" - just squeezed with my fingers. It was to the point of pain, tears rolling down my cheeks, sore fingers for days - but it worked.

Next I tried using several layers of tape to try and spread the load on my fingers. This reduced the pain level a great deal and allowed me to finish the job.

A set of leather work gloves might be another good way to go, but I haven't tried this.

89911 · 07:41 PM

It amazes me how similar frustrating events reappear on this board. I just did this last week when I replaced the dust boots. The fronts-no problem. The rears

. The problem is that the metal ring fits so snug, your fingers have little leverage to press it down without another side poping up. The solution: Take two old pencils and cut them so that when you place them inside the caliper, the eraser end is against the rubber seal and the other end is pried against the other side of the caliper, holding it snugly down. These are really acting as two additional fingers. Once these are holding the boot in place, it will either rock back and forth. Hold one side down and then use a blunt instrument to push the remaining edge over the metal piston wall. VICTORY.

Early_S_Man · 02-07-2002, 10:22 PM

Had you applied silicone grease to the inner portion of the new seal before attempting to seat the seal?

gchappel · 02-10-2002, 08:55 AM

Thanks, the "pencil" trick and some grease worked great.
Actually I cut some 5/8" dowel rods to the correct length- sanded them down smooth and for a good snug fit. I used 4 of them, one every 90 degrees. The first 3 went on easy, the last one was tight-but after a few seconds the metal band would pop right on. Did all 4 in about 10 minutes- no tears and no sore fingers

. Thanks again for all the support