Brake disc wear

Pneumatic · 07-31-2008, 02:32 AM

Hi to all

I'm new to the X3 experience but wish I'd got one years ago now! Just bought a 'approved used' (used to be called second hand didn't it) 2.0d sport and I love driving it.

I've just noticed that the front discs seem to be well worn - there's quite a lip on both sets at the front - does anyone know what the acceptable minimum thickness should be? I'm assuming a wear indicator light would come on if it was dangerous.

Car has done 45k miles

Thanks

Johnn · 08-01-2008, 12:35 AM

Judging rotor wear from feeling the amount of lip is misleading. Some have more of a lip when new than others. My '04 with 21K highway miles, has a definite lip, and I know the pads (original) are less than 20% worn. As you probably know, German vehicles tend to coat their wheels in brake dust - meaning that the design consideration is to not go for harder pads (and consequently greater rotor wear).
Not aware of any warning light associated with rotor thickness - just the usual things (fluid level, ABS, pad thickness).
Most X3 owners get in the range of 50K -65K miles before pads and rotors need replacing, but of course, driving style and urban/highway mix are a big factor.

Pneumatic · 08-01-2008, 02:10 AM

Many thanks for that erudite reply John, excellent advice - you've put my mind at rest. I'll ask the garage where we bought it just to have a quick look to see if they say the same as you, then I can show off with my (newly acquired) knowledge.

Goosey4370 · 04-17-2013, 10:58 AM

The warning light is for pad wear and not the discs.

Only BM can advise you of the minimum disc thickness, but, as a rule of thumb if you can feel more than a 3mm lip then it's time for new discs.
In my experience, depending on how heavily your general braking is, a set of front discs should last up to 30k miles. If you have any mechanical aptitude, both pads and discs are very simple to replace and if selected carefully, the cost should be below £100 for the set.

07-31-2008, 02:32 AM	#1
Pneumatic Pneumatic 1 Rep 2 Posts Drives: 2004 X3 2.0d sport Join Date: Jul 2008 Location: Lancs, UK iTrader: (0)	Brake disc wear Hi to all I'm new to the X3 experience but wish I'd got one years ago now! Just bought a 'approved used' (used to be called second hand didn't it) 2.0d sport and I love driving it. I've just noticed that the front discs seem to be well worn - there's quite a lip on both sets at the front - does anyone know what the acceptable minimum thickness should be? I'm assuming a wear indicator light would come on if it was dangerous. Car has done 45k miles Thanks
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08-01-2008, 12:35 AM	#2
Johnn New Member 0 Rep 13 Posts Drives: 2004 X3 2.5i Join Date: Feb 2008 Location: B.C., Canada iTrader: (0)	Judging rotor wear from feeling the amount of lip is misleading. Some have more of a lip when new than others. My '04 with 21K highway miles, has a definite lip, and I know the pads (original) are less than 20% worn. As you probably know, German vehicles tend to coat their wheels in brake dust - meaning that the design consideration is to not go for harder pads (and consequently greater rotor wear). Not aware of any warning light associated with rotor thickness - just the usual things (fluid level, ABS, pad thickness). Most X3 owners get in the range of 50K -65K miles before pads and rotors need replacing, but of course, driving style and urban/highway mix are a big factor.
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08-01-2008, 02:10 AM	#3
Pneumatic Pneumatic 1 Rep 2 Posts Drives: 2004 X3 2.0d sport Join Date: Jul 2008 Location: Lancs, UK iTrader: (0)	Many thanks for that erudite reply John, excellent advice - you've put my mind at rest. I'll ask the garage where we bought it just to have a quick look to see if they say the same as you, then I can show off with my (newly acquired) knowledge.
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04-17-2013, 10:58 AM	#4
Goosey4370 New Member 0 Rep 16 Posts Drives: X3 30D M-Sport Join Date: Apr 2013 Location: UK iTrader: (0)	Front disc wear The warning light is for pad wear and not the discs. Only BM can advise you of the minimum disc thickness, but, as a rule of thumb if you can feel more than a 3mm lip then it's time for new discs. In my experience, depending on how heavily your general braking is, a set of front discs should last up to 30k miles. If you have any mechanical aptitude, both pads and discs are very simple to replace and if selected carefully, the cost should be below £100 for the set.
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