let my stuck cylinder in my brake caliper set over night in pb blaster and it works like new. all the nasty rust is gone! woo hoo!

Awesome! I'm going to have to try it. Normally I use kroil.

Uh, clean the snots out of it with alcohol before you reuse the caliper. PB+ brakefluid = seals in rest of brake system swelling a leaking.

Oh good point. You don't want any contamination in the brake system.

how can it get into brake system by applying to cylinder?

 

If i'm not mistaken...brake fluid doesn't circulate.

Oh sorry man, I though you removed the brake hose banjo and shot it in there. At least that's what I did with kroil. Fortunately I had a caliper reseal kit onhand. The brake fluid does to a degree circulate. There's fluid going into the caliper when applying the brake. And fluid leaving the caliper when the pads get knocked back by the rotor.

I shot it on the piston and pushed it back with a c clamp and hit the breaks and sprayed it and pushed it back with a c clamp and hit the breaks and sprayed it and pushed it back with a c clamp and let it sit all night.

Oh ok, well that's cool that it helped. You should be fine in this case. Behind that rubber flex boot thingy is the piston, and inside that about 1/3" inch is the piston seal. Unlikely any pb blaster got into the brake fluid.

 

On my '94 I had a sticky caliper. I pounded the piston out with a punch through the caliper bolt hole. It was all corroded and stuff well into the piston beyond the seal. I cleaned it up with extra fine emery cloth, cleaned with brake clean, poured fresh brake fluid over it, and reassembled with the reseal kit.

Awesome! I'm going to have to try it. Normally I use kroil.

 

Kroil will dissolve rust and penetrate exceptionally well also.

 

Jack