Brake grinding noise

[DustyC]

'96 Golf TDi

Intermittant problem. Under heavy braking there is a horrible grinding noise on the nearside. Under no braking it sqeaks until the brakes are gently dabbed.

This fault began to occur about 2-3 weeks after new disc and pads were fitted.
I have taking it to a VW technician and he cant find any problems either!

Ive tried braking hard to dislodg anything but it still persists.

It also seems to occur after 30mins of driving.

WHAT IS IT?

[timbrown]

it's the dual mass flywheel which has parted company with the drive by wire sensor while you were sideways and caught up between the disk and your left shoe ..... maybe ?
or am I on the wrong thread ?

[DustyC]

If only it were that simple!

[GreenV8S]

If it happened right after the brakes were serviced, you probably aren't looking for worn parts or trapped stones, but there may be a clearance problem. For example if the disc dimensions were just slightly out, or a spacer added/removed between the caliper and the upright, you might have ended up with marginal clearance between the rotor and the caliper so that when the rotor heats up and expands it starts to foul the caliper. In particular the rotor diameter increases significantly when it gets hot so worth making sure you have a good mil or so between the outer face of the rotor and the bridge of the caliper. If it's been scraping for a while you may be able to spot witness marks - although I've found that even a very light contact can cause quite nasty graunching noises so the marks may not be at all obvious.

[DustyC]

Peter, That all sounds pretty good. Didnt see any obvious marks though.
Will take another look in these areas. It doesnt do it until I've been driving for at least 30mins so I reckon it must have something to do with heat expansion.