Stuck Caliper.....Thoughts
 

Have a Stuck Caliper that making the dam vehicle shake really bad. I am looking at rebuilding the caliper, Looking for any Do's and Don't from the ones that has done this.

Secondly, if I have to replace the caliper. Has anyone "pinched" the brakes lines to prevent air from getting sucked into the lines? A little scared to do this :cool: I would hate to damage the lines

If you're serious about fixing and not replacing the caliper, you need to remove it from the car.

You'll lose some brake fluid but you can plug the brake line. You'll get air in the system but you can bleed this out after you're done repairing the caliper.

When you have the caliper assembly out, clean it and try and figure out why it's seized. Did you run the pads down (i.e excess heat causing the piston to sieze)? Is the assembly rusty? Can you move the pistons with a vice grip or a vice? Do the pistons look ok? Is there uneven wear on the brake pad / disc from the caliper?

Be careful with the brake lines / don't pinch. Deal with the air after the fact with a bleeding. Use a piece of wood (something that gives a bit) between the vice and the piston if you're using a proper vice.

If your caliper piston is frozen, it may be because of bad fluid, so it may be worth it to flush and bleed with some fresh brake fluid.

Werewolf, I installed the rotos and pads on the less than a year ago (less than 10K miles) At the time I cleaned all the parts with plenty of brake cleaner and so forth. Running ceramic pads minimal brake dust. The pistons didn't look corroded at all.

As far as taking the caliper out. Do you think, I should open the brake fluid reservoir, loosen the caliper brake line and let it slowly drain out due to gravity. I have changed brake calipers before but I am really scared about air getting in the system and having to go to the stealership at pay them to blled the whole system.

Any thoughts on what I should do to the brake line, after I remove the caliper?

Yeah, I think thats a great idea. I think I will go ahead and bleed the system out.

anybody use this from harborfreight to blled the brakes. I don't have anyone to help me out with the brake bleed job.

- Harbor Freight Tools - Quality Tools at the Lowest Prices it?

Rebuild it with OEM kit- call your parts dept or call bavauto
 

If you have some time to wait for the part to arrive, bavarian auto sells a remanufactured caliper for a great price. Problem is they do not stock them. Need it fixed immediately, get the rubber gasket rebuild kit from BMW and do it in your garage.

Word of caution: READ THE DIRECTIONS FOR THE KIT AND FOLLOW THEM! Especially about the part of using compressed air to place rubber around piston. Ask me how I know.

My pedal went to floor after all work was done after two bleeds. Had to take to dealer. I figure air got in system and freaked out the ABS module. Dealer bled for $133 and we are good to go! Good luck.

do you care to elaborate on the "compressed air to place rubber around piston"? not sure what exactly you are talking about? How did air get in?

To rebuild a caliper piston, you need to remove any corrosion on the piston itself and the caliper seat where the piston moves back and forth. Also you need to replace the rubber seal that keeps the piston seated airtight in the caliper. The piston moves using brake fluid pressure, but once the caliper is removed from the brake lines, you need something else to push out the piston. That's where an air compressor comes in. You need to force air pressure into the caliper to push the piston out.

If you don't want to rebuild, buying a remanufactured caliper is the easier route.

For brake bleeding, I've used a Motive brake bleeder which I think BavAuto also sells rebranded as their own.

I wouldn't open the resevoir (that promotes fluid loss). When you detach the brake line from the caliper, simply cap the end of the brake line (you will lose fluid and it is nasty stuff).

Check the site for a DIY on brake bleeds. I think there is a way to open the ABS sensor gates so air doesn't freak out the module. There should also be a bleeder valve on the caliper for the excess air once you're done. This is not the same thing as the connection between the caliper and the brake line. After your caliper is finished and you bleed the brakes, you can reset the ABS sensor gate.