987-Disc Brake Pitting

[Tony C]

Hi All

I am a new member in the Thames Valley area and I would appreciate your advice:

Following a recent Porsche Reading service, it was identified that I had some internal corrosion on both the front and rear discs of my 2010 987 Cayman. I was wondering if anyone had tried the disc skimming service that is available at Porsche independent garages and was this successful?

Unfortunately, Porsche main dealers do not offer this service, with a preference to change the discs at some considerable cost. The performance of my brakes are a little noisy on the first few brake applications after setting off, but the performance is unchanged from a braking point of view. Once off on a drive they are fine. I always drive the car after washing to clear the discs of water and cover the car during the week as I commute to work by train.

Independent garages that are close to me are Hillcrest, Northway Porsche and Autofarm.

many thanks

Tony

 

[968CSReading]

Not tried them for disc skimming but couldn't recommend Northway enough. Only ever took my 968 to OPC Reading once. Alway used Northway or Wrightune. Not only are they cheaper but they have a lot more experience of the older cars. Give them a ring to see what they say.

 

[Tony Parker]

+ 1 for Ray Northway !

 

[spyderman]

OPC Silverstone skimmed the discs on my 986 in it's first service after I bought it. I've since learnt to dry the discs before I put the car away after washing it!

Chris.

 

[924nutter]

I am not understading why Porsche Centres are not offering the on car brake disc skimming service as it was a much vaunted aspect of their service when the region has been invited to an open day and actually I though it was a brilliant idea because it meant that any run out at the hub due to creeping corrosion between disc and mounting flange and makes the disc faces run true to the perpendicular of the axle centre line. It is interesting that all that clever equipment is now lying redundant. I have a pet theory the the internal faces of the discs corrode because the vents in the disc effectively suck the crap and moisture onto the disc face in the airflow that goes into the centre of the disc and exits radially from the edge of the disc. This must splatter the internal face. I can't think of any other reason why, in my experience it is always the inboard face that gets it. I had it on my 944 t which has four pot calipers as Ipresume the 987 so its not a case of the sliding caliper sticking and only operating properly on one disc face.

 

[Boxxster]

Hi Tony,

Welcome to the club, I have a 3.2S 987 which needed all 4 discs (inside faces) skimmed when I bought the car from Alexander David in Sunninghill , which they organised with some other items identified by the
OPC Check I put the car through. Not sure where they had it done, but that was 2 years ago and all is well so far. As Chris says earlier in the thread, drying the discs after it is washed helps , although
I think mine were rusty due to lack of use before I bought it as it only had 27k miles over 8 years on her.

Cheers Chris

 

[white944]

I used to use a Pro-Cut on vehicle brake lathe when I was running the workshop for another marque and it was a superb bit of kit. Gives an as new finish and takes out the combined disc/hub runout and any thickness variation that would normally cause brake judder at speed. Highly recommended to recover expensive discs that are still within manufacturers' wear tolerances.

 

[Tony Parker]

I have noticed that the discs on my 987 will show rust overnight, however the ones on my 968 never rust at all. Perhaps this is something to do with the quality of steel used ?

 

[graham.webb]

Could be something to do with the changeover from disc pads containing asbestos? I've a vague recollection that when this was introduced the metallurgy of brake discs was altered to work together with the new compounds. Brake dust never used to be the issue it is now!

Someone will be along, no doubt, to confirm or refute this...

 

[924nutter]

Graham is so right, and actually new asbestos free pads are not as good based on this. Owning a 924 my very first Porsche I used to go through brake pads about every 8-10 month (last of the late brakers me) then I was rooting around in Halnords or somewhere and spotted some pads for the 924 and though I'll have those so I bought them. Now someone is going to say that they never made asbestos pads for the 924 but this set must have laid at the back of the shelf for a while, and I am convinced that they were asbestos pads because the first time I stuck them on late I nearly went through the screen and the inertia reel locked up. They were definitely greatly different to the previous set of pads, and due to the age of the pack i have awys been convinced they were asbestos pads. I could see no otherexplanation for the huge difference in initial bite and greater efficiency. They faded less, if you pedal a 924 quicky you willl quickly learn about brake fade with its solid audi 100 based disks. As conan doyle said in the Holmes character, "when you have removed the impossible, what ever remains must be the truth no matter how improbable, and for once I did not have to clean my LeMans wheels every three journeys.