Anyone with real experience in Repairing/Rebuilding Rear Calipers?

[Peter Schulz]

Bernie/Folks:

Wide distribution due to the fact that those of us not in warm, dry climates suffer the malady of emergency brake cable/caliper issues.

I tried to disassemble one of the 200's rear calipers yesterday.  I removed it from the caliper carrier, removed the emergency brake return spring,  and brake hose.  Took it to the bench.  Using the Lisle "Cube" tool to turn the piston out of the caliper body - removed the piston and its boot.  Removed the inner dust shield from the piston cavity.  Looked into the piston cavity and saw the threaded rod to which the caliper piston is attached, and further inside, about three inches or 7.5 cm was a circlip that appeared to separate the piston compartment from the emergency brake cam and rod.

I tried to remove this circlip using two different circlip pliers, then a pair of long needle nose pliers, to no avail - either the piston rod was in the way, or parts of the caliper body got in the way of the pliers.  I even tried a pair of small philips screw drivers inserted in the circlip holes.

I finally surrendered, pried the cam and rod out of the caliper body as far as possible, sanded it, sprayed it with Wurth Rost-off, worked it back and forth until it would easily move, covered the exposed area with synthetic brake grease, and pushed the cam and rod back into the caliper body.  I then cleaned the piston cavity, lubed the piston with brake fluid and reassembled the caliper.

Now the ebrake cam mechanism is moving easily enough that I probably did not have to completely dis-assemble the caliper, but I still _want_ to see what's going on back there...any tips advice, etc?

BTW - I did notice that completely removing the piston from the caliper appeared to allow more of the ebrake caliper rod to be exposed to cleaning, than just prying it out and moving it back and forth with screw drivers and pliers.

There are some good existing instructions and guidance at http://www.urs4.com/technical/repair/ebrake/ebrake.html and also at:
http://20v.org/brakprob.htm#handbrake - I wanted to take it to the next level, however.


TIA!

-Peter

Peter Schulz
1990 CQ
1991 200 20v TQW indigo mica
1991 200 20v TQW titanium grey
Chelmsford, MA USA
peschulz at cisco.com