Anybody have a good trick to freeing up the piston on frozen wheel cylinders? i got mine off today and already have the rebuild kit for them, unfortunately i cant get the piston out of the cylinder. Any help or advise would be appreciated. thanks

 

I wonder if the bleeder is removed and a grease zerk installed, you could pump grease into it forcing them outward? I dunno might be worth a try.

Either that, or drill through one, and insert a punch, and pound one out, then pound on a socket for the other one. (better to use press)

 

We half-threaded a grease zirc in our brake line fitting and they just eased on out when grease is applied. The threads of the zirc weren't right, so, we just eased it in a thread or so by hand.

 

Doesn't sound like these are a good candidate for rebuilding. If there's that much rust, you'll be way oversize by the time you clean up all the pits. You don't say what model or year your truck is, but brand new wheel cylinders are rarely more than $15.

 

I have successfully used compressed air starting at 20-30lbs and slowly increasing. Just be sure to keep body parts out of the piston/spring flight paths.

 

That's the nice thing about hydraulics. No "blammo!" upon pressure release. I do have to agree that it is likely that these may be "toast." I find that the pistons lose their plating and corrode. New pistons from a similar cylinder and a steel sleeve can help a hard-to-replace unit.

Edit - cellphone-induced typo.

 

ok, they are from a 49 f2, which looking at LMC are a bit pricy, ill look around and see if i can find a cheeper outlet for them.... thanks

 

Try your local NAPA store. Rock Auto also has them listed.