wtb original kz900 caliper.

well, my front* caliper is seized. time for a new one.

EDIT:*

If not already tried, there are several methods to un-seize them. Some being more aggressive than the standard compressed air technique.

Good Fortune!

Pm sent

Here are some of the various methods which might be used to attempt removing a seized piston from the brake caliper.

Would first soak the caliper in Kroil, Liquid Wrench, PBBlaster, or 50-50 ATF/acetone mixture, or other penetrant, for at least a day, or even longer, in an effort to help loosen the piston.

Then use compressed air -- at least 100 psi -- through the fluid intake hole (where the removed banjo bolt attached), trying to blow the piston out of the caliper. Use a pad over exposed end of the piston. And keep fingers and other body parts clear of the piston when it shoots from the caliper. Leave the bleeder in its usual tightened position so air won't escape through the bleeder.

If unsuccessful, may boil the caliper in water for a minute or so, then remove and immediately re-try the compressed air. Also, try turning the piston if able to grasp it without damaging it.

Could also re-attach line to master cylinder, and try using normal brake line pressure to push out the caliper piston.

If caliper still won't budge -- may try using a grease gun attached to the bleeder nipple. Use a bolt to block off the banjo bolt hole. And pump grease pressure into the caliper, which might be sufficient to press out the piston. Again, keep body parts out of the line of fire.

Finally, there's the truly desperate fix-it-or-kill-it mode --- fill the caliper with water, close the air valve, block the intake, and put in freezer. Either piston comes out or caliper bursts.

Good Fortune!

Once removed, would clean up the piston (remove rust and corrosion) with fine steel wool or otherwise. Same for inside the chamber. The main idea is to achieve a smooth enough fit whereby fluid under pressure won't leak past the piston and seal.

If the caliper bore seems okay, the piston may be replaced if necessary.

Good Fortune!

This thread is temporarily relocated to the Chassis forum, being incident to the matters of attempting to remove the seized caliper piston and possibly restoring the existing caliper.

Good Fortune!

These....
kwickstand.net/Hyper-Formance.com/KWICK_Kaliper_Pliers.html

These are inside out vise grips that are modified Armstrong brand. They sell two sizes. The guy here buys the smaller size and cuts/modifies the jaws to fit into smaller multiple piston calipers. They make a larger size that works easily for large, single piston stuff like the KZ. Can find them on Amazon for like $20.

Cory

I don't know if using fine steel wool is a good idea. Scotch bright would be better. Steel wool will imbed fine partials of steel into the aluminum alloy used in the caliper which will lead to dissimilar metal corrosion. I used to get a kick out of the guys who cleaned up their aluminum wheels with steel wool. Looked great when they were done but a week later looked like caw caw again.

The caliper piston in my Z1B was stainless steel and was sticking because of some parts on the outside of the piston was corroded and interfering with brake pad movement. A well sealed air hose with 120 psi to the line opening should blow your piston right out of the caliper so be careful. good luck.

got together with a few guys at the machine shop i work at and tried pulling the brass fitting so we could connect an air line. we tried everything aside from drilling out and re tapping to the next size. that fitting will not come out. as stuck as it is i gave up on the piston.

the last straw was when the vice grips sheared the head.

time to pony up.

If you cannot repair your caliper, I might have a used operating one. Send me a picture of exactly what you have so I can compare. If I have one, it will not be too expensive for sure.
Thanks
e-mail holiday442@charter.net if you need me to look at my parts.

Can you carefully use a drill but set in 32nd's of a inch and slowly keep drilling out the remaining portion of the fitting until you weaken the barrel of the fitting and the tension in the threads let loose? I have done this many times with over tightened and corroded fasteners while still leaving the female threads intact.

Cory

Where are you located? I'd be happy to free it up for you. FREE