Brake caliper sleeve repair

[dbeardslee]

So I got some SS brake lines for Betsy, and since she's been sitting for a few years I decided to rebuild the calipers while I was at it. When I got them off I found I that I couldn't move the caliper sleeves at all - those suckers were locked up tight. They're supposed to move freely so the brakes will release properly, and they also need some movement so the calipers can adjust themselves as the pads wear down. At any rate, the condition they were in was not good, and probably contributed to the notchy feel I was getting at the lever.

Since I didn't have new boots, and something needed to change, I decided to see what I could do about repairing the old ones. First I disassembled the calipers completely, and then I went to work on freeing up the sleeves. I used some silicon spray on them, and shot it in where I could and kept applying pressure back and forth. As I got them to move a bit I kept applying the silicon spray, and managed to get them to break loose. Then I pulled the sleeves out, followed by the boots, gave them a liberal spray and rubdown with silicon, and set them aside to dry.

Next I cleaned out the hole the boot lives in - which was pretty cruddy - with a battery terminal brush and white scotch brite pads. Then I cleaned the whole caliper with brake parts cleaner and reassembled everything. To my delight those caliper sleeves move easily now, and I'm pretty confident they'll work like they're supposed to.

At any rate, if you're doing a brake job don't forget those sleeves. They're pretty important for the proper operation of the brakes.

[natemoen]

Make sure to pull the o-ring seal in the caliper that the piston slides against. Clean out behind the o-ring, that is where the Pistons usually bind.

Also remember that silicone and brake fluid are not compatible (unless it is dot 5).

[natemoen]

Also, if the caliper pistons are rusted and pitted you can get replacement stainless steel pistons from HVC Cylce.

[dbeardslee]

Make sure to pull the o-ring seal in the caliper that the piston slides against. Clean out behind the o-ring, that is where the Pistons usually bind.

Also remember that silicone and brake fluid are not compatible (unless it is dot 5).

Which is why I used the silicon before I sprayed everything down with brake parts cleaner. I used silicon because I didn't want to booger up the boots by using a petroleum based product, and silicon is easy on the rubber. Once I had the boots out I set them aside while I used the brake parts cleaner on the rest of the caliper.

I don't generally take brake calipers apart without replacing the seal, boot, and retaining clip since the opportune time to change parts is while you've got it apart. So in keeping with my MO I replaced all that stuff, as well as giving them a thorough cleaning. The right side caliper and piston was in pretty good shape, but the piston on the left had some pitting, but it was out beyond the seal so I just cleaned it up and replaced it. I also hit the cylinder bore on that one with a brake cylinder hone.

But I'm not sure I buy that the seal was what was causing the notchy feel. Those caliper sleeves were really stuck, and it has to be able to move on that sleeve for the brakes to work properly. I could feel the difference in the way the calipers moved when I put them back on, and while the pistons were still retracted. Nice and smooth.

I did run into a problem with the SS line that runs from the master cylinder to the "Y" connector - as in it was a couple inches too short. I put the old line back on top 'till I get a replacement from the vendor, bled the system, and took her for a test drive. The brakes are nice and smooth, and the notchiness is gone. The lever is a little on the spongy side, but I've got her in the mancave with the brake lever tied back, and I'll let her sit like that overnight to let the remaining air in the lines bubble to the top. Tomorrow morning she should be golden.