It's time to get back on the old race bike. Took a few weeks off due to the holidays, some travel, and building some solid struts for the old Digger. But, I'm focused on getting this pig up and running in time for summer.
After some cussing, clever back-filling, and a mity-vac, I was able to get the front brakes working flawlessly. I'm very pleased with how they feel so far, and upon inspection, the rotors and calipers are in fantastic shape. Once I bought all new lines, crush washers, and spent some time bleeding, they're perfect.
The rear brakes are a different story. The rear master I got with the bike was frozen solid and after I tore it apart and thoroughly cleaned it, it still leaked air. So, I bought a second-hand master and this poor gal was in even worse shape.
BUT, after some scrubbing and a mix and match of useable parts, I was able to turn 2 masters into 1 good one.
I bled the rear brakes, got all of the air out, had a good pedal feel but the brakes still didn't work. I pulled off the caliper, got the rubber boot removed and saw a rusty, frozen piston. BUMMER. Still, I wanted to recycle the parts so I went along with trying to use it. After pulling, whacking, heating, air-blasting, and lubing the caliper, I just couldn't get the piston to move.
I had heard about a neat trick using a grease gun to push out a frozen piston. Evidently, you plug the banjo bolt hole, loosen the bleeder and pump grease into the caliper until it forces out the piston. Sounded pretty messy put I wasn't left with many options. So, a $15 grease gun and some creativity and WHAM, she popped out! I can't recommend this method as once you're done, you have a grease filled pile of junk... but it worked. haha.
At any rate, sadly the piston was rusted, pitted, and completely unusable. Fuck it, I'm buying a new one. I found brand new xs650 Front Calipers that APPEAR the same... unless anyone objects, I'm going to snag one and see if it fits. We'll see!
http://www.tcbroschoppers.com/yamaha-xs650-front-right-brake-caliper-fits-1977-1984.html