rear caliper piston replacement

[portlandgrey]

Changing the rear pads yesterday & my N/S caliper has a torn seal & corroded piston.
I managed to get it cleaned up enough for the caliper to work ok for now, but will look to sort it out next week.

Does anyone know the part number or a source for replacement pistons/seals?

I've checked real oem & it dose'nt show the piston part no.
Is it shared with any other BMW?, i've read it may be the same part as fitted to the e93 M3, but can anyone confirm the actual part number needed?

[NZ_M3]

34216753682

[awbmw]

NZ-M3, just tried to PM you but getting an error message saying your inbox is full...

[shawn 968cs]

I believe the rear pistons are not available from BMW, and there is a problem with the only other source (name alludes me at present, Redish supplied mine) as they are too long, there isn't any date for correct length ones. They have also modified the seal to prevent the corrosion.
However the longer ones can be turned down if you take care on a lathe.
There is also the option of having the existing ones plated up with chrome and grinding them back to size (they grind the corrosion off first)
There is a company in Gloucester that can do this.

PS the corrosion is normally not in the working area of the pistons, hopefully just on the extremities.

Rgds
Shawn

Originally Posted by portlandgrey

Changing the rear pads yesterday & my N/S caliper has a torn seal & corroded piston.
I managed to get it cleaned up enough for the caliper to work ok for now, but will look to sort it out next week.

Does anyone know the part number or a source for replacement pistons/seals?

I've checked real oem & it dose'nt show the piston part no.
Is it shared with any other BMW?, i've read it may be the same part as fitted to the e93 M3, but can anyone confirm the actual part number needed?