When I get this thing running, it would be good to have at least some brake functionality. So, I’ve started rebuilding the front brake.
I used a spare Aprilia master cylinder to blow the pistons out of the caliper. Handy tip: Put the caliper inside a 2-gallon ziplock bag to avoid an unexpected spray of brake fluid.
The whole thing was filled with crud, and I needed both cylinder pressure on one end and the Mityvac pulling on the other to clear the line. Eventually, a big black plug of gunk appeared in the bleeder tube. Once it was through, I had no problem popping the pistons out.
There was a lot of baked-on crud outside and some jellied residue inside, but overall it was not bad. I was prepared for much worse. The pistons could be easily reused, but I have already purchased new pistons, seals, and boots.
Next, it all goes into the ultrasonic cleaner!
Ultrasonic bath, then soda blasted, back in the ultrasonic tank again, then a couple coats of Eastwood Brake Gray. We’re ready for reassembly.