09-29-2019, 10:24 PM | #1 |
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Minimum rotor thickness ?
From https://www.newtis.info/tisv2/a/en/f...rakes/KmlF6cl2
it shows this " Important! Installation of new brake pads is approved only provided that the brake disc thickness exceeds the specified dimension for "MIN TH" (see table). Brake discs must be replaced when they reach the nominal thickness (see table) minus 2.4 mm! (Not applicable to perforated brake discs and M vehicles) . Applies only to M vehicles and perforated ventilated brake discs: The brake discs must be replaced once they wear to the nominal specified thickness (see table) minus 1.6 mm! " Nominal size (diameter x thickness) mm 340x30 (MIN TH) is stamped in brake disc chamber mm 28,4 So if I read this correctly..... New pads can be installed on existing rotors as long as thickness is > 28,4 and rotors must be replaced when they reach 30 - 2.4mm = 27.6 Is this correct? And also "M vehicles" means M2, M3, M4 so not applicable for the M2XXi ? |
09-30-2019, 03:04 AM | #2 | |
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Rotors replaced at 28 because of scratches and minimum thickness
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They were at the minimum but had scratches on them so could not be resurfaced and still meet the minimum. I can get more specific info from service ticket if you want it. 228i with THP |
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09-30-2019, 10:05 AM | #3 |
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On the other hand, my dealer did the first rear pad replacement and only resurfaced the rotors under warranty (about 20k miles); IIRC the paperwork showed that it had .002 or .001 left above minimum after the resurface. I'm told that it is about impossible to find a dealer willing to do that for you out of warranty, instead just spouting that old line: "they are designed as a set, new pads, new rotors". Given the labor, and the fact that they will need replacement in just a few thousand miles, I'd do rotors too unless you do the work yourself. The upside to all this lack of 'serviceability' is thinner discs with much less rotating unsprung weight, which is a benefit to all performance aspects.
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07-25-2021, 12:04 AM | #4 |
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Anyone know the minimum for the rears? I know they come brand new at 24mm.
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07-25-2021, 11:44 AM | #5 | |
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Quote:
Minimum brake disc thickness stamped on brake disc chamber mm 22,4 Installation of new brake pads is approved only provided that the brake disc thickness exceeds the specified dimension (see table). Brake discs must be replaced when they reach the nominal thickness (see table) minus 2.4 mm!" so you can only install new pads on the rotors when thickness > 22,4 and you need to replace rotors no matter what when they reach 21.6 = ( 24 - 2.4) |
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07-31-2021, 11:19 AM | #6 |
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Thx Pikca!
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'04 E46, '08 E93, '16 F22 M235i, '17 i01 i3
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