Audi A6 2008 one pad wearing quickly at rear

[dan2485]

If you do get stuck the nipple is a M10x 1mm pitch.

The motor bolts are M8x22 T30 cap head bolts.

If you take off the motor you should be able to wind the piston fully out with the adjuster.

The piston just sits in the adjuster, remember to fully wind it back in on the rebuild and carryout the calibration/function test with VCDS on refit.

[Strath44]

Thanks Mate,

ok so everything was seized completely and to cap it all off the key snapped in my garage door!

on the plus side I eventually freed off the bleed nipple and the bolts on the guide pins also there is indeed a tear in the piston boot!

tomorrow I will run vagcom and release brake to remove calliper.

i will need a bleed nipple which is a worry on a Saturday but the current one is ok I guess in the mean time (can you grease them to prevent seizing?)

when you talk about winding the piston out does that avoid having to run air through it to pop out the piston?

normally I have my smart meter charger attached throughout any brake repairs, do I leave the motor cable connected and just remove the motor?

[dan2485]

If you have freed of the nipple it should be fine.

The caliper is very simple there should be no need to use any air to push out the piston, just wind the adjuster out with the motor off.

You may need to unclip the boot on the piston.

if its stuck in then you need to pressurize some fluid to get the piston out.

Im doing mine on sunday, If you are renewing the small O ring on the adjuster then once you release the C clip lift the caliper off the adjuster and do not pull the adjuster out of the caliper as the roller bearing is at risk of falling apart.

Remember to clean the caliper properly and use emery cloth to remove any high spots of rust.

As long as you turn the ignition key to off then you can remove the caliper whole but do leave the charger attached and clear any faults when done and run the calibration once the parking brake has been set to close.

[dan2485]

P.S. clamp the brake hose before you start and top up and bleed the brakes when the job is done whilst looking for any leaks.

[Strath44]

thanks that's a big help!

just to clarify,
I can unwind / release the epb with vcds as per usual
Then clamp the brake fluid line
remove the caliper
Remove the motor
Wind out the piston

upon re-fitting the piston i take it I fully wind back in the adjuster then fit the new piston & boot

I would normally finish the standard pad job by closing the epb via vcds, does the motor and epb module relearn the position of the adjuster within the caliper - ie as long as i fully wind it back in upon refitting the motor it should be ok?

[dan2485]

All of the above is correct

The calibration/functional test aligns the brake properly.

[Strath44]

hey, bit of an update!

I ended up taking the caliper off the car as it was going to be ten times easier to work on!

I had to unscrew the brake hose at the caliper as the upper connection looks very rough!

got the caliper off, both torx head motor bolts snapped which is a pain, i hope i can drill them out but a bit sceptical.

thanks for the tip on winding out the piston that worked perfectly and everything cleaned up well, I ended up taking everything apart as I was worried about dirt.

i assume the brake fluid lubricates the bearing race? is there any grease I can use for assembly?

Going to try penetrating fluid then heat on the snapped bolts tomorrow I have a cheap pillar drill so that will be next, any tips or suggestions appreciated!!!!

[dan2485]

You know what your doing with the drilling out and then run a tap through the holes.

I' m going to do mine today, I have a feeling that I have the wrong piston kit as the piston that I have is 42.8 mm.

I have like you a 1KD rear caliper.

I will measure my one on the car before I take it apart.

I went on the year of manufacturing of the car.

Thanks for for the update.

[dan2485]

Yep the wrong kit, so a new p138 kit ordered. Will do it next weekend.

[dan2485]

how did you get on today?