M3 brake judder

[MPETT]

I've had my m3 8 months now and had noticed in medium to heavy braking a judder from the brakes. I've just had a service 2 undertaken and the problem went away for a week then returned. I ask the mechanic what he'd done and all he'd done was lube the calipers.

Upon changing my wheels for my summer wheels/tyres, I noticed brake buildup in the cross drillings of every disc, so I used a drill but to clean them out. The problem has now gone!

So before u spend a small fortune, make sure your discs are nice and clean!