juddery brakes

[TheAngryDog]

the brakes on my M5 are juddering, though they only seem to judder after the car has warmed up a bit.

Is this likely to be the discs or the pads, or something else?

[Foretrees]

if its any help just had first service on my 640 with 9000 miles and new front discs were fitted, i had a brake judder at 40 / 50 mph on light braking, just drove home and it feels fine now, the garage did a disc run out and the front were faulty.

[ecain63]

Means your brakes are worn. My M5 did this when the brakes got toward the 40k mile mark. New discs AND pads will solve it. The juddering is caused by uneven expansion of the discs when heating up as opposed to uneven wear or warping. You don't get a lot of tolerance with the discs on these cars.

[Captainawesome]

ecain63 said:

Means your brakes are worn. My M5 did this when the brakes got toward the 40k mile mark. New discs AND pads will solve it. The juddering is caused by uneven expansion of the discs when heating up as opposed to uneven wear or warping. You don't get a lot of tolerance with the discs on these cars.

Yup agree with this, just had the discs and pads done on my M3. They were ok cold but once hot would judder like crazy. New p & d and perfect again.

[Cambell]

I changed the front discs and pads on my E60 M5 for the same reason. I got them on eBay from CotswoldBMW very cheap.

[TheAngryDog]

Cheers guys, thought it would be the brakes, just didn't want to spend £400 on them to find out it wasn't.

[M3CS]

I've got this problem on one of my fronts (MOT diagnosed the exact disc at fault; gave me an advisory). I'd rather not shell out for front brakes twice in 18 months, so I'm probably going to try a Pro-Cut brake skimming service near me first (costing £70); then replace the fronts if that doesn't work.

Anyone have with experience using this service? Is there any 'danger' in it damaging any components such as the hub?

[ecain63]

^^^ check disc thickness. The minimum allowance is stamped on the bell. You dont get much tolerance with M discs

[shim]

Some good advice here

[LocoBlade]

May well be worn discs but it could be as simple as pad material collecting on the disc surface causing the judder, especially if you have soft performance pads. It's an easy (and free) fix if it is, just take the wheels off and give the discs a rub down inside and out with some reasonably coarse wet & dry sandpaper (dry), then wipe off any dust with some brake cleaner.

[M3CS]

Yer, EBC yellow stuff pads. May try this tomorrow. Thanks.

[nickfrog]

LocoBlade said:

May well be worn discs but it could be as simple as pad material collecting on the disc surface causing the judder, especially if you have soft performance pads. It's an easy (and free) fix if it is, just take the wheels off and give the discs a rub down inside and out with some reasonably coarse wet & dry sandpaper (dry), then wipe off any dust with some brake cleaner.

Agreed it could well be that. Or a brake bedding exercise might help clean up the residue. It will go eventually (500 miles?).

A visual inspection would give a bit of a clue (post a pic) or just a feel with the fingers. A disc that is glazed with pads material will often feel like it's scored (but it's not).

[malman]

M3CS said:

Yer, EBC yellow stuff pads. May try this tomorrow. Thanks.

This recommends garnet paper rather than wet and dry which is usually aluminium oxide.

http://www.stoptech.com/technical-support/technica...

[TheAngryDog]

Brakes changed. No more judder.

[M3CS]

Got the fronts skimmed earlier this week for 80 quid. Needed to drive very carefully at first, as the pad and discs begin as a different shape, so wasn't able to rely on the brakes being 100%. About 200 miles later and they seem to be back to normal: great braking performance and NO JUDDER!

Very happy. I recommend this fix: 'Pro-Cut brake skimming' (google it!)

[batmanreturns]

My discs were knackered so i got them replaced to cure the juddering but it's still there! It turns out it's control arm bushes which is a common issue around 80k miles so check these first before the discs-much cheaper!!