Continued working on the brakes for my '73 Dart Sport. Finally got the pistons out of the calipers....whadda job!!!
Tried everything, including compressed air...yeah, I know...dangerous. Used penetrant oil to try and loosen and lube the internal seal a little.
I almost gave up and was thinking of just ordering new ones from RockAuto, but I decided to give it one more good shot: I loaded up my grease gun with a fresh tube of grease and put a rubber tip on it. Made sure the bleeder was closed, crammed the rubber tip into the threaded hose connection and pumped the grease to her while tightly holding the rubber tip in there....viola!!! The piston moved on out to about the last 1/4" or so. Some gentle taps with a hammer and punch around the outside edges and they were out.
This method cost me about 3/4 of a tube of grease but it was worth it to get em on out.
Pistons looked great and no serious pitting in the cylinders!!! I was pretty concerned since they've been sitting in the shop for over 17 years...LOL
Glass bead-blasted the internals clean, including the seal slots, etc. Washed everything completely spotless with brake cleaner. Made sure the piston fit without the seal first.
All was good and assembled with new seals using a tad of silicone grease for lubricant. Got one completely rebuilt and ready to install on the car. I should have the other one ready to go by lunchtime tomorrow. Getting this old gal back to roller status has been a chore....but I love it. :)