Rear Piston Won't Adjust

[testrider]

As you may have read elsewhere my 2000TC fail the MOT on the rear brake power and hand brake power. I tried manually operating the caliper with the handbrake quadrant and I could hear the adjuster mechanism clicking, but it didn't make any difference.

So, today I removed the calipers from the car to strip them down and find out what's going on. On the bench it's impossible to wind the piston back in, but it would turn the opposite way. With the cover and all the internals removed I've found I can't unscrew the knurled wheel.

It seems to be seized on to the threaded sleeve that is in the centre of the piston and with a bit of persuasion I got the whole lot to turn, but the sleeve turned with it. I presume it's not meant to turn, so how can I get it all to unscrew? And, if I can get it to bits can it be reattached?

 

[harveyp6]

If the inner sleeve in the piston cup is turning independently of the outer part, then that's scrap, and so if that's the case, check the teeth on the ratchet (what you call the knurled wheel) and if any of those are damaged, then that's scrap as well, so just cut it off. Otherwise you need to unscrew the ratchet from the piston cup, and if you can do that without damaging either of them, and you inspect them both for damage and they're OK then they can be used again.

 

[testrider]

Thanks Harvey. The ratchet does look worn so it's all knackered.

Reckon I might have to go for a set of reconditioned calipers then.

 

[harveyp6]

Reckon I might have to go for a set of reconditioned calipers then.

I have a used ratchet I think, and if Dave3066 doesn't want it at the moment, I have a serviceable (although not great) piston cup. Personally I would never pay someone else to overhaul calipers. The last few "reconditioned" calipers I've been involved with have all needed taking apart and putting together properly...