Brake caliper rebuild

This seemed like such an easy task before I started it.  I wanted to go through the front brake caliper and make sure that everything inside was good to go. Well I split the caliper into halves and took a look under the brake pads which looked nearly new.  Underneath was a different story, RUST, so much rust.  See brake fluid is hygroscopic, meaning that when exposed to the moisture in air it pics up water and the water then causes the system to rust from the inside out.  Couple this with sitting for several years and you get brake pistons that look like this.

To get to this stage, I had to free the pistons from the caliper body which took reattaching the master cylinder to the caliper and refilling the system with brake fluid and putting pressure on the pistons which helped me get them unfrozen but not all the way out.  For that I had to stick an air hose in each side and blow compressed air in while trying to keep from blowing the piston into my face.  This was not easy.  Once I got the pistons out I inspected the rubber seals and the pistons and found that there was no way I was going to be able to reuse these again.  I was lucky to find a company that manufactures stainless steel pistons for the caliper at $80 a pair, which isn't great, but helps me feel better about the stopping on the bike (when I first test rode the bike the front brake wasn't working at all, which was interesting to say the least).

After getting all of the parts in I cleaned all of the rust out of the caliper body and bore and worked on changing the rubber seals.

Then the final challenge was getting the pistons back in with the new seals.  The tolerance is so small on these that this was no small order.  I manged to get both of then partially in, but had to use a c clamp to get them the rest of the way seated.  Then fully assembled final product:

I didn't paint this part like all of the others for a few reason, first there wasn't a lot of rust on the outside and for the most part it looks pretty good.  That plus the fact that brake calipers need special paint due to the high temperatures and corrosive brake fluid, I thought it best to leave it and see how it looks on the finished bike before bothering to refinish it.