I was surprised at the loud popping noise they made when breaking free of the bore. I need some new shorts anyway.

Pssssttttt . . . . BANG! POP! Owwwwww! Never had it happen to me. I always wrap a rag around the area where the air gun goes into the brake line hole and put one over the pistons as well. Flying brake fluid is definitely not good for your eyes.

for future thread searchers, you can also use a long bolt of the same thread pitch as the input line. Just screw it into the back and it will contact the piston and push it out.

Not sure how that's gonna work as the tap width is much wider that the small hole that resides at the bottom of the inlet port.

Not sure how that's gonna work as the tap width is much wider that the small hole that resides at the bottom of the inlet port.

screw it in and the end of the bolt will push the piston out as you do.

Better be careful with this "bolt into the caliper" trick. I an not certain the threaded hole is not a pipe thread or has a seat built into it. Stick with the air pressure and don't mess with the threads is my advice. (IMHO)

even if the bolt trick worked (and I'm not too sure it would) that would still leave the piston in the other side of the caliper to deal with.

IMO air is the way to go, just watch where you park your pinkys.

even if the bolt trick worked (and I'm not too sure it would) that would still leave the piston in the other side of the caliper to deal with.

IMO air is the way to go, just watch where you park your pinkys.

On opposing piston brakes it would. I can't remember what the stock 240s are as I don't have them anymore.

As for the thread pitch, its 10mmx1.0 and there are no seals. My home business is powdercoating brakes, and I do 10-30 sets per month, but mostly corvette brakes now.

The point is, there is one seal inside of a brake and it runs the circumference of the pison, right next to the pad. Brakes are really simple, once you've taken them apart.

This is on the same track as with the front caliper piston removal...

I have a stuck wheel cylinder piston I am trying to rebuild. For the life of me, I cannot pull it out, or even spin it, for that matter.

I tried cleaning it out with B12, then spraying PB on it, let it sit for an hour, tapped on it for about 5 mins, and nothing. I even tried spraying with the airgun into the brake-line fitting threads with 125PSI...nothing.

I filled the area around the piston (where the aluminum housing and piston meet) with PB and let sit overnight...nothing.

What more can I do? Does anyone know where I can find a left side wheel cylinder, new? Not on e-bay very often.

Just replace them with rebuilt ones.

Just replace them with rebuilt ones.

I have the rebuild kits, I just need to remove the piston from the cylinder...

If the piston is that stuck it probably isn't worth rebuilding.. But if you must, try using a small C clamp and try pushing it in, that may break it loose so it will come out. You should be able to find a new one at NAPA for around $20 or so.