Hi, I'm looking for a decent rear caliper for 1981 gl1100. One without a stuck piston like my original. I have a rebuild kit on hand but can't get the piston free.
Sorry I do not have a caliper but would like to suggest making an adapter so you can use a grease gun to pressurize the caliper you have and pump the piston out. This is the method we used in the shop and cannot remember not being able to get a piston out.
Yeah I haven't really worked on it much but did get the piston to go in a 32th of a inch or so with a bench vise. I was going to try some heat from a heat gun and try to work it out.
I have always found the bleeder thread size is much smaller than zerk (grease) fittings (except for some trucks). For brakes with banjo fittings I have made adapters that mimic the banjo (same thickness and hole size) and have a zerk fitting installed perpendicular to the banjo bolt (see sketch). I also have adapters where I have used a bolt with the same thread as the banjo bolt or brake line fitting that is center drilled and taped for a zerk fitting. It is amazing all the stuff one accumulates over the years. To sum things up use hydraulic pressure (ie grease gun) to press the piston out.
Should be able to unscrew the grease gun end a bit ...and it should fit the bleeder ..then screw it tight and pump grease gun ...I’ve never had it fail to not push piston out ...