997 Brake disc ridges

[jerseygirl]

997 S2 needs new front pads - not sure whether to change the discs at the same time as they have a small ridge on the outer and inner leading edge ?

[Rockster]

jerseygirl said:

997 S2 needs new front pads - not sure whether to change the discs at the same time as they have a small ridge on the outer and inner leading edge ?

As long as the rotors are thick enough and have no other problems that would render then unsuitable for service...I've changed the pads on my Boxster more than once with the ridge present with no ill effects.

If you want to go to the trouble you can take a coarse file and file a small bevel at the pad edge that is closest to the rotor's outer ridge and the pad edge nearest the rotor's inner ridge, but I've never done this with my Boxster when replacing the pads, but years ago I used to do with other cars. But I've gotten lazy. And it really isn't needed in my experience or of course I would do it.

Be sure you bed in the brakes to well bed the new pads to the worn rotors.

Sincerely,

Rockster.

[MadMark911]

IMHO - As soon as the lip is close to 1mm (and you can really feel it when it is), then it's time to think of changing them as the there will be a similar amount gone on the inside (and you've then lost roughly 2mm of disc thickness). Often the corrosion kills them before they get this far anyway!

I'm about to have mine done this month as they're nearing the levels described above and are corroded on the inside (despite the pads only being 35% worn)! The previous owner was obviously much gentler on his brakes than I am ....

[FarQue]

Err, why not measure the thickness of the discs and compare the result with the recommended tolerances?

[Pickled Piper]

Another option is to get them skimmed on the car. This will get rid of the ridges and any surface rust.

pp

[MadMark911]

FarQue said:

Err, why not measure the thickness of the discs and compare the result with the recommended tolerances?

Fair enough! These are the new / wear limits for the OP to compare to:

Brake disc thickness, new (front) Measured value 34 mm
Brake disc thickness, new (rear) Measured value 28 mm

Brake disc wear limit, front Measured value 32.0 mm
Brake disc wear limit, rear Measured value 26.0 mm