Front brake discs

Guest · May 5, 2006

I am sure I am not the only one to suffer rusting on the inner front disc surface on my 2002 3.2s.The car has only covered 20000 miles and I have been rigorous in regard to proper drying of the brake disks after washing.I have had Mercedes,Volvo and Volkswagen high performance vehicles in the past and have never had this problem before.Porsche discs do seem to be particularly prone to this defect.Can any one suggest a suitable replacement that will not rust so easily?
The car is still under warranty and the Nottingham dealership have already skimmed the discs once already.

Rotorhead · May 5, 2006

Do your Merc, VW, Volvo have drilled discs?

The water collects in these holes and, if not dried, runs onto the inside of the disc. If the car is then left unused for a while the rust can progressively accumulate.

Usually it's the inside rears that can rust as the brake bias is to the front. Not a warranty item though.

PCCBs don't rust[&:].

critch · May 6, 2006

My experience with many cars of all makes is that the inside faces of the discs always corrode more than the outer faces, drilled or not. I think this is because it is difficult to wash the salt from the inner faces of the discs in the winter. I have noticed, however, with my new 987S that the discs do seem to go brown quicker than, say, on my Volvo S80, or on my wife's X-Trail. I now make a point of directing a good jet of clean water onto the inner surface of the discs from underneath the car. This would be easier with ramps, but if you are prepared to crawl around on the floor it is possible. Will this make any difference? No idea! I guess only time will tell.

Critch

Rotorhead · May 6, 2006

The best way to dry the discs after cleaning is to go for a drive, and the combination of airflow and heat (through brake testing) will do the job.

sawood12 · May 7, 2006

Where are they rusting? Is it on the actual pad swept area or the top hat part of the disk? I know that on the later Porsches (996's and probably Boxters) the top hat part of the disks does rust where on the earlier Porsches (993 and earlier) they didn't so it seems Porsche has 'cheapened' the disks somewhat, whether they are using a different material or just not treating the material in the same way they used to I don't know. A mate of mine with a 996 has painted his disk top-hats with a heat resistant paint.

Geoff_Fields · May 8, 2006

993 and older disks had higher chrome content, hence they didn't corrode. I believe the reduction in chrome was to reduce brake squeel but more likely to save money!