Rebuilding calipers - need C clamp to push piston in?
 

When rebuilding SC calipers, the primer in the tech section says....

"Insert the piston seal into the groove in the caliper bore, and insert the piston. It should slide in a short distance without too much effort. Don’t force the piston, and be careful not to get it cocked in the bore. Orient the piston at a 20-degree angle from the top of the brake pad slot in the caliper."

I just rebuilt mine and the only way to get the pistons in was with the brute force of a C clamp. The pistons are definitely not skewed or binding on the cylinder walls. Is this common? Per haps I had the wrong size seals? Thanks

did you check the cylinder bore for pits, corrosion or wear? Did you soak the piston seals in brake fluid before installation?

The insides of the bores looked very clean and I used clean brake fluid to lubricate the piston and seals. Again the question, should they just slide in by hand? I'm wondering if I got a set of seals that are too big.

Yes; you should be able to smoosh them in there with your hands.

Definitely should be able to push them in with your hands - may take some effort but definitely not a C clamp. If it takes that much to push them in when they are dry and outside of the car, they will drag when they are installed.

George

Remove that one and remove the seal and see if you can slide the piston in the bore (without the seal) and check for binding. It will fit very close. use plenty of brake fluid as lube. If it does not fit, there might be some corrosion around the bore or you scored the piston with the C clamp and it must be replaced. Be careful!

Thank you all. I guess this explains why I can't lock my brakes up. Our minivan currently has better stopping power....I'll buy and new rebuild kit and open everything up for a second look.

Ate has also a special greese for the pistons... i used it.
http://www.alfabb.com/bb/forums/atta...lutch-lube.jpg

i have a set of those big pliers from sears, they are great for brakes.