Mystery Brake Pad wear

[TWO]

Please can anyone advise on the strange wear pattern on the rear discs on my Z3, 2.2.......the same on both rear discs!

As you can see the discs have worn from the inside of the diameter and on the reverse side have worn by a similar width but from the outside diameter of the disc........as if the calipers are twisting.

There was flexing of the caliper when I levered the spring clip out with a screw driver using the hub as a fulcrum, BUT all fixing points appear to be absolutely rigid.

I will clean every thing back to 'new' when I replace the pads; but in the meantime please can members advise on the cause............is it in any way effected by a leaking brake servor?





Many thanks

[wildeboy]

Hi TWO,

That slider looks pretty corroded, if you take out the pads does the caliper slide smoothly front to back. It doesn't look like it will!
The caliper is probably twisting rather than sliding causing the pads to only touch on the inside at the front and outside behind the disk.
you might be able to remove the sliders and clean them up although I doubt they are very expensive to buy new. If the rubber guides are shot you will probably need new or reconditioned calipers.
Hopefully a 'proper' expert will be along in a minute!

[msassoon]

That sounds right to me, the pistons need removing and cleaning or replacing. A good clean should be enough.

[seaDog]

Yep one of your sliders is sticking. Biggred do a caliper repair kit for £22.90 del, which is enough to do both rear calipers. You will need to replace the plastic guides and regrease the sliders. While you are at it, strip the piston out, clean it up and replace the old with new seals that come in the kit.

If youve got some brake line clamps you won't need to bleed the brakes afterward, you need the caliper off the car to fit the new seals.

Jas

[TWO]

[quote="seaDog"]Yep one of your sliders is sticking. Biggred do a caliper repair kit for £22.90 del, which is enough to do both rear calipers. You will need to replace the plastic guides and regrease the sliders. While you are at it, strip the piston out, clean it up and replace the old with new seals that come in the kit.

Cheers Jaz

I have the complete calipers off at the moment, including the carrier frames, and are in the process of cleaning all of the items back to clean metal prior to painting...........the pistons move freely

Excuse my ignorence; but I have not heard of 'Bigred' ........can you post their details

Once again thankyou, and other members for their help

[seaDog]

Biggred are brake specialists

Click here to go to their website.

You get all new seals in the kit so you might as well replace the piston seals as well while you are at it. Clean up the metal slider pins and regrease and then fit the new plastic guides in the caliper x2. If you want me to do a picture how to, let me know.

Jas

[TWO]

Hi Jas

PM sent