My left rear brake caliper has been leaking for a while. I got to this yesterday. I finished it this morning. The re-build isn't really very difficult; many threads and references to this job. But, pictures help us to understand so here are a few:
The trick is cutting down the end of a C clamp to fit. I used a Dremel cutting wheel. This one came from Home Depot, less than $10 as I recall:
A fat file used as a screwdriver to remove the piston off a threaded shaft. Both calipers are standard threads. Once the piston is removed, the task is to remove this same threaded shaft by working on its other end under the rubber boot:
As you pull back on the rubber boot, the threaded shaft it held tight against the parking brake actuator by a series of spring washers. They are in series like this ()()(). The C clamp is used to flatten them so that the actuator can be removed after the retaining circlip is removed. There is a small key which will fall away during this process. It is not symmetrical so be careful to observe its orientation so that you can reinstall it correctly (I assume it makes a difference. I'd hate to find out the hard way
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) Take note of the spring washers also. So, the notched end of the C clamp is placed on the small extended end of the threaded shaft shown in the photo.
Once the actuator is slid free, the shaft can be pulled out. There is a small o-ring on the threaded shaft and a rubber seal inside the actuator cylinder. Clean everything well, inspect the surfaces and re-assemble. I used wheel bearing grease on the spring washers and shaft and on the new seals and where the boot sits. I also used a long wire tie to better seat the edge of the rubber boot. I installed the piston dirt seal by sliding it up onto the piston. After screwing in the piston a ways, I worked the caliper edge into its groove with a small screwdriver. Once the piston is fully screwed in, the seal slides over the piston crown on its own.