Hey guys. Had to replace my rear rotors and pads. They were bad.
All went well on my passenger side caliper but my driver side is stuck. The inner caliper adjusted and collapsed in just fine for the new pads. I removed the outer plug and used a 5mm allen to adjust it but it would not move. I tried turning both ways. Now the allen adjuster part on the inside of the caliper comes out and I can't get it back in to adjust.
Is there a way to collapse the caliper without this or is it completely shot? I used a C-clamp to try and compress it but it is going nowhere.
Looking for suggestions....Thanks.
Full Version: Rear brake caliber shot?
Send both calipers (or all four) to pmb performance. They will restore to new. There’s really nothing more important on the car than your brakes.
Also replace rubber soft lines if it’s been years since last replaced.
Also replace rubber soft lines if it’s been years since last replaced.
you can not compress with a C clamp
its gear driven, and you will only break it
usually an air wrench will spin fast enough to re-engage
otherwise, pull the caliper and you can drive it out, when the caliper is apart.
its gear driven, and you will only break it
usually an air wrench will spin fast enough to re-engage
otherwise, pull the caliper and you can drive it out, when the caliper is apart.
We're talking the outer piston, yes? That one is not gear driven, it's thread-driven. The inner one is the gear driven one.
Are you saying that you backed out the screw (counterclockwise) so far that it detached from the piston threads? You can lightly push in the outer caliper piston to try and re-engage the threads. But I don't know what you mean by "allen adjuster part on the inside of the caliber comes out" because that screw cannot "come out" of the caliper except through the piston bore.
Be careful; there's a very small o-ring on the inside of that screw shaft, stopping brake fluid from leaking out. If you damage that o-ring you'll have to remove the caliper to replace the o-ring.
I'm going to guess that the reason this happened, that your piston did not move when you turned it, is because you're missing the little circlip on the end of the threaded shaft. That circlip is what the nut that you loosened pushes against in order to retract the piston. Without that circlip it will draw the shaft in, instead of retracting the piston. A lot of people will remove that nut completely and bugger the circlip; it's only intended to be a lock nut. Loosen the nut, adjust the allen screw, tighten the nut.
I actually need a couple more of those circlips; I'm missing one and the other is buggered...
Are you saying that you backed out the screw (counterclockwise) so far that it detached from the piston threads? You can lightly push in the outer caliper piston to try and re-engage the threads. But I don't know what you mean by "allen adjuster part on the inside of the caliber comes out" because that screw cannot "come out" of the caliper except through the piston bore.
Be careful; there's a very small o-ring on the inside of that screw shaft, stopping brake fluid from leaking out. If you damage that o-ring you'll have to remove the caliper to replace the o-ring.
I'm going to guess that the reason this happened, that your piston did not move when you turned it, is because you're missing the little circlip on the end of the threaded shaft. That circlip is what the nut that you loosened pushes against in order to retract the piston. Without that circlip it will draw the shaft in, instead of retracting the piston. A lot of people will remove that nut completely and bugger the circlip; it's only intended to be a lock nut. Loosen the nut, adjust the allen screw, tighten the nut.
I actually need a couple more of those circlips; I'm missing one and the other is buggered...
I'm going to guess that the adjuster assembly inside the piston has come loose. PMB is the way to go. Not the cheapest option, but you won't worry about your rear brakes for the next 35 years, if you take care of your 914. I used to rebuild most of the calipers that I work on, but now that's the exception, I just send the to PMB
First of all, you are discussing calipers, not calibers. Search won't work if you use the wrong term.
Both pistons are adjusted via a threaded shaft within the piston. And yeah, the inner also has a gear that reverses the direction as well.
If you loosen the outer lock nut, and the circlip is properly in place, but you get no movement with adjustment then you have a serious problem that only a pro can repair. Like Perry, I have rebuilt these calipers for 40 years. Some are real buggers and I need all the tricks I have learned.
At this point, just send them to PMB for remanufacturing. If the adjusters are buggered they can replace them. Same with the pistons and all the seals. Not really worth doing the rears yourself.
Both pistons are adjusted via a threaded shaft within the piston. And yeah, the inner also has a gear that reverses the direction as well.
If you loosen the outer lock nut, and the circlip is properly in place, but you get no movement with adjustment then you have a serious problem that only a pro can repair. Like Perry, I have rebuilt these calipers for 40 years. Some are real buggers and I need all the tricks I have learned.
At this point, just send them to PMB for remanufacturing. If the adjusters are buggered they can replace them. Same with the pistons and all the seals. Not really worth doing the rears yourself.
Well guys, I was totally wrong with side of the caliber I was having trouble with. It was the inner. The outer went in fine. However, I did have some fluid leak out so I may have ruptured the o-ring as mentioned in a earlier post.
The inner one is the one that is locked up. It would not go in or out when turning the adjustment. Now the adjuster is out and will not go back in.
The inner one is the one that is locked up. It would not go in or out when turning the adjustment. Now the adjuster is out and will not go back in.
The caliper (not caliber) needs professional help now. Send to PMB!
^^^What he said.
PMB can direct-ship with a core charge, and once you send yours back they'll refund the core (as long as it's rebuildable.)
I have come to seriously hate those rear calipers.
PMB can direct-ship with a core charge, and once you send yours back they'll refund the core (as long as it's rebuildable.)
I have come to seriously hate those rear calipers.
It's CALIPER
QUOTE(euro911 @ Jun 18 2020, 05:39 PM) 
It's CALIPER
Yup caliper.. I was thinking auto correct was to blame but its a pattern.
This is a "lo-fi" version of our main content. To view the full version with more information, formatting and images, please click here.