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Discussion Starter #1
Hey folks. I injured my back a few years ago, and had to store the bike for a few years. Now that I'm up to riding again, it's time to start figuring out what failed while it was sitting.

First up is the front brakes. I pulled them apart this morning (calipers, master cylinder, and all), and here's what I know is bad:

Caliper: Most of it seems to be in OK shape. The pads need to be replaced, which is easy. The big issue is that the pistons are completely frozen: I can't get them to budge even a little. I'm assuming they'll need to be replaced, IF they can be removed.

Handle/Master Cylinder: Somewhere along the line, the piston assembly sprung a leak. The whole thing is going to need to be repainted, the piston assembly is thoroughly stuck, and every screw in the entire assembly was apparently replaced at some point with low quality screws which are now mostly rust. Oh, and I suspect the brake-light switch is going to need to be replaced. The diaphragm isn't in great shape, and the rust issue includes the screws holding the cap on the reservoir.

The hose is a total loss, which doesn't surprise me.

I have a set of brake pads and the seals for the pistons, but I'm looking at a minimum of $30 each for the pistons, however much a new hose costs, and $50 or so for the diaphragm/cap/screws for the reservoir. Basically, the parts are going to be a minimum of $150, probably more.

My question at this point is whether it's even worth trying to salvage. What would I be looking at for new equipment? Am I likely to be able to find something better for not much more?

Thanks in advance, all.
 

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You can get the pistons out by pumping brake fluid behind them with the caliper disassembled. This will require a working master cylinder. You might do best to simply find another one at a salvage yard; buying online from a reputable used parts dealer may also work.
You don't necessarily have to stay with parts specific to your bike- the most important thing about the master cylinder is that you match the bore size- this is generally cast into the body of the master cylinder on the underside, and expressed as a fraction of an inch (1/2. 9/16, etc). You could use a master cylinder from a Kawasaki or Suzuki or whatever, so long as you match the bore diameter and get the banjo bolt that goes with the master cylinder (different makers use different thread pitches on the master cylinder). You'll have to keep track of the make and model that the master cylinder came from in case you later need to get a brake lever.
Once you've got a working master cylinder, it's just a matter of filling it with fresh fluid, getting the bubbles out of the system, and then pumping fluid into the caliper. Keep track of the fluid use as the pistons are driven out of the caliper. If the pistons don't rise evenly, use a "C" clamp to restrain the more readily moved piston so that both come out.
The pistons themselves may just be crudded up with dried brake fluid and dirt. If you clean them up and the surfaces that contact the seals are good, you're okay. If there's pitting or scratching where the seals ride, then it's time for new pistons.
 

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I have the master, hose and caliper I just pulled off my '82 available. It's complete and functional, add pads bolt on an go. PM me if your interested.
 
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Discussion Starter #5
Since I hate leaving threads unfinished...

Despite some minor issues, I got a working setup from HamHock, and gave it a semi-substantial test-ride yesterday. Brakes now work fine, and the bike has passed inspection.

Thanks again, HamHock!
 
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