RS man

Excuse my ignorance chaps.
I have noticed some fine (hairline) cracks(?) on the drilled brake rotors. Does this mean that the discs need replacing?

Harry

Eric in Chicago

Harry,
Not until the cracks reach the edge of the disks or until they start to play connect the dots (holes) with each other.

RS man

Thanks Eric. I can go to bed now!

Harry

Ray Calvo

Actually, to give you nightmares, Porsche sez to replace them if the cracks get longer than 7mm (about 1/4 in). The cracks don't connect, in my experience (5th rotor set in 77K miles); they radiate in a radial direction in and out which is not in line with the other drilled holes. So you might take another look and maybe plan a replacement.

RS man

Woke up with the nightmare of changing the discs!! Thanks Ray I'll check it out.

Harry

N105DVV

Someone told me once to dechamfer the hole edges, seems that it reduces the tendency to crack.

BR/Phil.....