Brake disks

Need technical Q/A then you're in the right place

Moderator: martauto

Post Reply
jslot
E30 Zone Regular
E30 Zone Regular
Posts: 456
Joined: Mon Oct 13, 2008 11:00 pm
Location: Isle of Man

Fri Jan 16, 2009 9:54 am

I would be grateful if someone could tell me,

How do I know when my brake disks need to be changed?

Could anyone give an approximate figure for how long standard disks last, with standard pads, and a normal driving style?

Are there any visual signs that a disk may be slightly warped?
Image
Alex
Married to the E30 Zone
Married to the E30 Zone
Posts: 22666
Joined: Fri Feb 11, 2005 11:00 pm
Location: Johannesburg, South Africa

Fri Jan 16, 2009 10:44 am

im not too sure but i think they need changing when they have an uneven surface and seem more black than silver :?:


oh and when you cant stop at lights you know they need changing winkeye
User avatar
zimmerbimmer1
BMW Parts Meister
Posts: 2250
Joined: Sat May 19, 2007 11:00 pm

Fri Jan 16, 2009 1:04 pm

Depends if you are a hard or soft braker

Fronts anything from 10k to 25k
Rears 15k to 40k
Image
User avatar
Brianmoooore
E30 Zone Team Member
E30 Zone Team Member
Posts: 49358
Joined: Mon Jan 10, 2005 11:00 pm

Fri Jan 16, 2009 7:52 pm

Minimum disc thickness is 20.4mm for the fronts, and 11.1mm for the rears. The figures are stamped into the outer edge of the discs, but are usually unreadable.
They also need replacing if they have deep surface corrosion or are badly scored, of course.
I usually reckon on changing discs every second pad change.
gareth
E30 Zone Team Member
E30 Zone Team Member
Posts: 11009
Joined: Tue Jan 11, 2005 11:00 pm
Location: hastings, east sussex

Sat Jan 17, 2009 12:17 am

if you're gentle with the brakes, you might find corrision finishes off the rears before the fronts.

as brian said, i generally use 2 sets of pads for each set of discs
Sole founder of Fe2O3-12V it's a lifestyle
Image
LSD rebuilding / modification services provided, PM for details
Post Reply