XSeries-forum

Looking on eurocarparts for pagid front brakes

They list two due to discs size. I’m not sure which discs size I have

But they said
Part number 101110638 is for 320mm discs, before discount £85.99
Part number 101110658 is for 365mm discs, before discount £82.99

Thanks

Part number 101110658 is for the twin piston caliper.

Is mine the twin piston?

Check Realoem.

Thanks

Had a quick look on realoem

I saw 365 as the brake discs
So are the callipers twin pistons?

Realoem slide....
http://www.realoem.com/bmw/enUS/partgrp ... 30sd&mg=34

Shows both front and rear caliper units as single piston, sliding assemblies (more correctly called ‘floating’ calipers) where the piston on one side only pushes the pad against the disc and the same hydraulic pressure forces the other side of the caliper (inc pad) to be pulled towards that side so creating a vice like grip.

Some calipers (not ours) use twin (or more) pistons on one side or both sides.  Where there are pistons on both sides then the caliper is fixed (can’t slide) and the pistons squeeze the pads.  Our calipers are only fixed on one side with the other side free to move - or float - towards it.

If you really want to know how they work then see this:
https://auto.howstuffworks.com/auto-par ... lipers.htm

Thanks

As my other post I’m looking at calliper repair kit

I thought it was twin piston
Maybe the single piston kit will be fine then

update whilst getting new pads fitted, my front caliper are twin piston on 3.0sd 2008 m sport model

pads worn badly and scored the discs badly so new pads ordered, collected and fitting tomorrow.
along with calipers rebuild possibly as one piston is stuck wide open causing the wheels to be hot