Brake Service
12-23-2019, 11:06 PM
#16
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Location: Marineland FL
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12-23-2019, 11:18 PM
#17
Racer
Thread Starter
Yes sensors can be reused if not triggered by warn out pads. Warn out pads are less than 2mm thickness. Some pads have ware bars (like tires) that will tell you how much usable pad is left
991 S (both C2S and C4S)
Front
new: 34 mm
minimum (after machining): 32.6 mm
wear limit: 32.0 mm
Rear
new: 28 mm
minimum (after machining): 26.6 mm
wear limit: 26.0 mm
991 S (both C2S and C4S)
Front
new: 34 mm
minimum (after machining): 32.6 mm
wear limit: 32.0 mm
Rear
new: 28 mm
minimum (after machining): 26.6 mm
wear limit: 26.0 mm
12-23-2019, 11:25 PM
#19
Rennlist Member
lip measurement is not important. measure the center of the rotor in multiple spots. Micrometer (C shape) calpiers work the best but Vernier calipers work if you can fit the lip in the gap.
12-23-2019, 11:31 PM
#20
Racer
Thread Starter
12-24-2019, 12:10 AM
#21
Rennlist Member
On my 2014 991S both front and rear OEM rotors have wear spec holes. These will look like cross-drill holes but are not drilled all the way through. If you can still see these then your rotor are still in spec. If you cant see these holes then you need new rotors. I would assume that all Porsche 991 OEM rotors have these wear spec holes. again these marks look like cross-drill holes but are shallow and not drilled all the way through the rotor. Go look at your rotors and report back. Im curious if you till can see them
12-24-2019, 12:12 AM
#22
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12-24-2019, 12:15 AM
#23
Racer
Thread Starter
On my 2014 991S both front and rear OEM rotors have ware spec holes. These will look like crossdrill holes but are not drilled all the way through. If you can still see these then your rotor are still in spec. If you cant see these holes then you need new rotors. I would assume that all Prosche 991 OEM rotors have these ware spec holes. again these marks look like crossdrill holes but are shallow and not drilled all the way through the rotor.
12-24-2019, 12:18 AM
#24
Racer
Thread Starter
I'd rather rely on sensors to tell when things are worn out.
12-24-2019, 12:26 AM
#25
Rennlist Member
Well it sounds like you should run what you have until the car tells you to change the pads and then do some new rotors at the same time. and maybe some new tires and some spacers and.......
12-24-2019, 01:37 AM
#26
Racer
Thread Starter
With current rotors and pads anything can be done to reduce the squeak? few hard braking? any liquid solution to apply?
12-24-2019, 01:11 PM
#27
Your measurement of those wear holes on the rotor doesnt sound the most accurate. I would get a mic and measure the rotors the right way, in a few spots. Take that number and remove the value the lathe operator told you he needs to machine off and see if you are within minimum thickness. If you are I would do that and put in some pads of your choice and run it for the next 20k miles before swapping rotors and pads again.
12-25-2019, 03:28 PM
#29
Racer
Thread Starter
For two and a half years they were totally silent. Then suddenly started to squeal.
12-25-2019, 03:29 PM
#30
Racer
Thread Starter
Your measurement of those wear holes on the rotor doesnt sound the most accurate. I would get a mic and measure the rotors the right way, in a few spots. Take that number and remove the value the lathe operator told you he needs to machine off and see if you are within minimum thickness. If you are I would do that and put in some pads of your choice and run it for the next 20k miles before swapping rotors and pads again.