Rear brake disc minimum thickness?

E

Easty-5

Member
 Aberdeen
What's the starting and minimum thickness for rear discs? I measured mine yesterday when taking my track wheels off and they are about 20mm. I can't find anywhere that states what the disc thickness is new though so I can gauge how worn they are. There is absolutely no lip at all on the discs.
 
328mm x 20mm

Min thickness is usually stamped on the bell somewhere.

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If your discs are just under minimum thickness it's not an issue until you need to change the pads.

I expected the dealer to change the rear discs on my DD when it went in but as they were above the limit when changing the pads they said no need.
 
Well according to this link, the Minimum for the Rear is 18.4mm :D

http://www.bimmerfest.com/forums/showthread.php?t=410494

Not sure how you have 20mm on worn rotors though, I would double check that, across the surface.

Just replaced my front discs, for the second time. My car's on 43k now. Have only replaced the rears once though.
 
buzyg said:
Just replaced my front discs, for the second time. My car's on 43k now. Have only replaced the rears once though.
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I'm on my 3rd set of fronts and 2nd set of rears - at 130k miles.

Just don't seem to need to use the brakes as much as I used to - must be slowing down in my old age (or not braking for corners anymore).
 
I'm on my 3rd set of fronts and 2nd set of rears at 48,000 miles. The joys of lots of trackdays, aggressive pads and using the brakes hard. I didn't realise the rears were so much thinner than the fronts. My discs will be fine then. Thanks.
 
I'm on 37k miles and I'm pretty sure PVR said the discs were the originals all round... Must check, as that doesn't sound right compared to you lot. I'll find out if they need changing at my MOT on Thursday, but they don't look like they're too bad tbh.
 
Bing said:
I'm on 37k miles and I'm pretty sure PVR said the discs were the originals all round... Must check, as that doesn't sound right compared to you lot. I'll find out if they need changing at my MOT on Thursday, but they don't look like they're too bad tbh.
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You had original pads as well, if you recall he did or tried to flog you some new pads for when the time came.

He is tighter than a Scotsman :lol:
 
I still have the original pads, and yes I bought the others off him as they're quality (apparently...) - he is indeed tighter than me... They don't need changed yet either, I need to do better like Flimper :D

Still got the original front tyres too, but they're almost done so I'll be putting the ones I bought from Mr Wilks on in a couple of weeks I think.
 
I'll take a look what my first set of fronts did. It was much further than the second set. I was never happy with them, they weren't worn out just didn't stop the car properly and inspire confidence. :thumbsdown: So I replaced them at last week Ins 2, even though there was plenty of meat left in them. Still OEM , as the originals were great. Only done about 40miles since (Bl##dy rain) but this set felt so much better from the off :thumbsup:
 
Right, well after a digging out the relevant Receipts, the first set of fronts were changed at 30500 miles, so the second set had done less than half that. Hopeful that this set will be more like the first. :)
 
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