PCCB on turbo and s with PVT

grover · Jun 25, 2012

I am interested on the forum here about people's experience with wear on the rear discs with PCCB.

Having done just 10800 miles and a couple of track days (one at Silverstone on their own track!) so hardly an all out attack event, the dealer is saying that this is normal wear and they need replacing.

My recent rip across europe and alps seems to have brought these to more prominense

You can see three ten mill circles on the disc where the material is very abrasive compared to the rest of the disc.

This seems totally unreasonable to me on a high performance car

Everything they market about these discs is low weight and long life based

Thoughts and experiences please?

Alex L · Jun 25, 2012

I think your PCCB might be a newer version than mine, but I have done 26k miles and 1 track day and last service I was told that the brakes were 50% worn.

How much are the OPC quoting you?

My Audi RS6 (hopefully selling this week) got through 80% of its steel brakes in 1 year (no track days) and they are over £2k for new front+rear brakes!!

spyderman · Jun 25, 2012

Whatever happened to "discs will last the life of the car"? My 2004 Boxster steel discs have done 17k miles and least 12 track days and they're still serviceable.

Rodney Naghar · Jun 25, 2012

Good to meet you yesterday, did you have fun?

My rears are gen I PCCBs with 45k on the clock and with over 20 track days are pretty much as new.
The 997 has more rear brake bias but that shouldn't warrant new discs so quickly. Can you post up a picture?

grover · Jun 25, 2012

My OPC isn't quoting me anything so far, I just know they are c£3k a corner, its me asking the question of them saying they haven't lasted long enough on a nearly new car, so the debate is just starting and to change them at £6k plus I think is unreasonable. I am with the sales manager all day at Goodwood on Saturday.

Yes to Rod Naghar, had a good time yesterday, getting some swift circuits too, that turbo "˜s' certainly goes well and the passengers all said they loved it and were surprised about the car compared with others around.

Lancerlot · Jun 25, 2012

12.5K on mine including a sprint race, several 997 tours and the Kings and Castles European Mountain Tour and my brakes seem pretty much as good as new.

I'd be inclined to ask for a review and further investigation of premature wear.

Let us know how you get on.

Regards,

Clive.

maxtraeger · Jun 25, 2012

My PCCB brakes are Gen1 from 2006 with now 43K on the clock with several track days, high speed driving in Europe and still no signs of wearing out. Why would the rear on your car wear out well before the front anyway?

Good luck in your discussions.

Max
997.1TT

Lancerlot · Jun 25, 2012

ORIGINAL: maxtraeger

Why would the rear on your car wear out well before the front anyway?
Max
997.1TT

"Porsche Torque Vectoring" uses the rear brakes to improve turn in cornering.

Regards,

Clive.

maxtraeger · Jun 25, 2012

Thanks for the update CLive - did not realise that Porsche would try to make more money ...again when ".... moderate brake pressure is applied to the inside rear wheel". Interested to know how the discussions unfolds.

Max

Rotorhead · Jun 26, 2012

Surely it's the pads not the discs that need replacing?

Peter_Bull · Jun 26, 2012

My Gen 1 with PCCB has 61k .

The car was a PC GB demo car, driven by Vic Elford round Monaco, so it guess it had some stick earlier in its life.

I have done two trips to Europe which incorporated two visits to the Nurburgring (7 x 14 mile laps).

They are still like new all round. Pads not even half worn yet either.

bobfair · Jun 26, 2012

I had a Gen 1 997 Turbo with PCCB and a Gen 2 GT3 also with PCCB. Both cars get used on track. Pad wear on the rears is much worse than the fronts. I change my pads every year (after 6 or so track days) to protect the discs. There is no way the discs should need replacing after 10k miles but it is quite possible the rear pads do need changing based on my experience. The Turbo is a heavy car and needs a lot of stopping. A complete set of PCCB pads will cost you around £1k from an OPC. I guy I did Ice Force with this year has done 200k miles on a set of PCCB discs so they will last a long time on the road.

The PSM system uses the breaks to stabilise the car by applying the rear breaks so if you are using the car enthusiastically on track pad wear is normally very high. There is also a HUGE difference between using the car on track and on the road the big difference being heat build up. Track use puts much more heat into the pads than normal road use. The standard Porsche PCCB pads dont stand up well to the heat in my experience which is why many trackies use aftermarket pads.

Just because you can see the circles on the PCCB disc doesn't mean the discs are shot according to my OPC. I can see the circles on my discs and my OPC says that is fine. I have never had a satisfactory answer of exactly what the circles on the PCCB discs mean so if anyone can shed light on that it would be much appreciated

andrew symms · Jun 26, 2012

my understanding from OPC tech was that when you cannot see the circles is when the discs are worn, this discussion held at the OPC clinic the other weekend.

grover · Jun 26, 2012

Thanks chaps an interesting set of replies to start the debate.

My dealer had said when the little disc marks are visible its time to change, they are also rough to touch at those points, if that means anything. No similar signs on the front ones.

David

Rotorhead · Jun 27, 2012

When PCCBs were first introduced (Gen 1 almost 10 years ago), apparently there were some issues.

However, the current (Gen 3) PCCBs incorporate numerous improvements in composition, manufacture, cooling, and longevity. There is slightly more rear bias than before, and some of the chassis aids utilise braking, but its the softer pads that are said to be more sacrificial.

In normal use, which could include some track use, the discs should last several times longer than steel rotors. To be worn at such a low mileage would suggest a manufacturing defect, or an extraordinary fault elsewhere in the systems - although I would still expect the pads to have gone first.

BTW, some PCCBs were replaced under warranty owing to damage resulting from wrongly torqued centre locks - for which there was a re-call.

Rodney Naghar · Jun 27, 2012

I'd be interested to see a picture of them. I've seen Porsche's own picture chart showing different wear rates so I could give you an estimate on the wear based on that

grover · Jun 27, 2012

Give me a few days and I will try and do this over the weekend

evansash · Jun 27, 2012

A mate had an Aston with these type of brakes and had to be changed after a few trackdays. 1st pads 6k miles, discs & pads 9k and Aston paid for the whole bill on the 9k change. He says in that he has heard about the sprays for wheel cleaning and silicone tyre pretty stuff causing contaminiation issues. My GT3 done 14k and look OK.

RJKflyer · Jun 28, 2012

I've noticed that rear pad wear on my steel rotored .2 TT is quite high, which I have put down to PTV. Also noted rear rotor temps similar or even hotter than fronts, which is a first for me.

Best brakes I have ever used, and unlike my two M3s and RS4, suspect I'll get more than 10k out of the rotors into the bargain... (to be fair a pad problem with RS4, not an undersize problem as with the M3s)

However, would be MIGHTILY irritated at PCCB DISCS wearing out at 10k...

Lancerlot · Jul 1, 2012

David,

Following further enquiries, I am informed the circles you describe are wear indicators and these are 3 placed at 120 degrees around the circumference of the rotors on each face.

The appearance of these indicators does not necessarily signify wear, since they can often be visible in new parts too. The minimum acceptable thickness is stamped on the brake disc hub (eg. Min.Th. 33.7mm)

Allowable accumulated surface roughness should be no more than 80 micrometres.

Regards,

Clive.