Corroded Discs?

[John H]

Porsche disks do corrode very easily, but regrettably many OPC's play on this fact to railroad customers into changing disks and pads as soon as possible. That said, at 4 years old and 25k miles, your disks probably are getting to the end of their days, especially if they are showing wear marks like the rings you mention. Is the car garaged? Do you religiously dry off the disks every time you wash the car? If not, the dreaded corrosion very probably has got a hold. My own car is just on 4 years old, has done 35k miles and is still on the original disks (although second set of front pads) and I reckon I will have to change at least the front disks fairly soon. The back ones get an easier life, and will last a bit longer. I am pretty light on the barkes, and I am fastidious about drying them after a wash, but I doubt if they will last much longer. You can of course buy the parts and do it yourself (not terribly difficult) or you could use a good indie who will do it for a lot less, but the sad fact is that modern Porsche brakes do not last long, and you will need to fork out sooner or later.

 

[spyderman]

If there isn't an appreciable lip, just get them skimmed.

 

[Peter Anthony]

I have read posts previously on corroded discs on this forum, but not being too good on the search facility couldn't pick up on them.

I had a four year service in May and the OPC omitted to do the brake fluid change, and I didn't check the bill or the service book properly! I recently changed my commuter Golf for a BMW and it highlighted the length of brake pedal travel in the Cayman so I visited the OPC today to ask they look at the brakes. I was shown the inner sides of the discs with the car on the hoist. The insides did have what I describe as mottled black colouration. Touching with fingers picked up black powder, I had given the brakes a good workout on the way to the OPC. The discs were also ridged with concentric circles, this didn't elicit any comment from the fitter when I mentioned it.
The service manager advises I need new discs and pads, some £1,500 all in. I have booked it in for the brake fluid change, and will see what happens to the quality of the braking after that. I don't have a problem braking, it just needs quite a bit or travel. OPC advised this will be because of the corrosion deteriating the grip of the pads to the disc. Fitter estimated 35% to 40% life left in the pads. Car has done just under 25k.

My gut feel is see what it is like post brake fluid change, then decide if I need replacement discs and pads. Seems sensible to have the fluid change done, particularly as it is a service requirement and I believe there is still value in the OPC stamps on a 4 year old car.

Any thoughts guys? Comments appreciated.

 

[Black80XSA]

28k miles, 5 years old and still on original discs n pads albeit some corrosion on inner faces of the rear discs. Find an independent to do the brakes if you do need them changing. £600 or more left in your wallet. Pedal travel and feel of the Porsche and my mk6 golf are completely different, albeit the VW is a lot less sharp in action than VWs of old.

 

[Christoff]

Hi i can answer any questions you have about your brakes, First of all John H is absolutely spot on saying that after 4 years they are probably at the end of their service life. And also with saying that they need drying off after washing by giving it a run up the road and back.  The best tip I can give you for prolonging the life of the discs is to use them regular.  Every now and then apply them as hard as you like and really test them out.  It helps to kepe them clean and efficient.  If you leave the car stood in damp conditions for long periods they deterriate rapidly unfortunately. I see lots and lots of discs that are corroded because of lack of use or improper use. The fact that John H is on the second set of pads on the front says that his brakes get used properly and as a result, they have lasted well. The rears are more suseptible to corrosion than the front because of two reasons, one is that the rear brakes do less work than the front.  The other is the way the airflow is directed to them.  Air is directed under the vehicle and onto the rear brakes to keep them cool, this carries with it moisture and dirt which can speed up corrosion. The brake fluid service is mostly to keep the fluid fresh rather than to bleed them.  A brake fluid change in a 4 year old Cayman should not effect brake pedal travel unless there was excess air in the system beforehand, but there shoudnt be.  The reason the fluid change every 2 years is because the fluid is hygroscopic (absorbs moisture from the atmosphere). 

 

[Peter Anthony]

Thanks for your comments, as ever the forum is a source of useful advice. I will see what the brakes are like after the fluid change, and while I am there get a quote from the OPC for the discs and pads, front and rear, I hope with the club discount of 10% off the parts, the price may be more reasonable. It seems absolutely right advice to also get a quote from a good indie who will use the proper Porsche parts. Will report the results in a few days. Thanks.

 

[John H]

I doubt if the fluid change will make much difference. I must have driven a dozen different Caymen now, and each one had a subtly different brake pedal feel. It's just the difference between individual cars. Worth noting that when the OPC does the disks and pads, they change EVERYTHING, mounting bolts, sensor wires, all the little clips and pins, etc. It is one of the reasons why the price is so high. I imagine very few indie's do this, and will re-use all the assorted hardware, and just change the actual pads and disks. The Porsche approach is possibly overkill, but there is no denying it is thorough.

 

[JohnP]

My local indie changes everything and will use either Porsche parts or OEM parts as requested. Even with Porsche's ridiculous prices the total cost was still considerably less than the £1,500 mentioned.

 

[bajers]

Hi Guys, Had the Cayman for less than a week now and just measured the discs yesterday. It looks like they are all below minimum thickness, although they don't look corroded. Wasn't really aware of braking issues with Porsche until after the purchase. Shows you the benefit (or the cost) of not doing your homework I suppose! Car has done 34000 miles, presumably on original discs, but virtually all motorway miles. Braking seems fine, but I don't have a reference of what it was like new and pedal travel doesn't seem excessive. Sounded Porsche Leeds out and 1500 seems the going rate from them to do the work. I can buy the bits for around the 500 mark or 'original manufacturer quality' cheaper than that and do it myself. Probably change the pads at the same time, although they are well within limits at the moment. Probably leave it until the spring and do it then. Issues around this and just thinking aloud:- If new discs are 24mm across the 2 discs, min recommended thickness around 20mm?? That equates to 1mm wear off each of the 4 faces before they need replacing which seems absolutely poor to me. Would you recommend using original Porsche discs/pads or go for the cheaper bits? I want to take a 3rd year warranty out next April, and Porsche insist they do an 111 point check on the car first so would the discs be included in this if I didn't get them changed? Would Porsche insist on doing this work themselves? Any thoughts on doing the work myself? Done brakes before but the thought of working on a classy bit of kit is putting me off a bit. I have started saving now because I think next year is going to be a bit of a drain on the old wallett!! Love the car though, absolutely love it. I do regret buying it last week though.......should have done it years ago.[]

 

[Peter Anthony]

Ouch! I have just gone onto the Porscheshop site and priced up discs and pads, both original Porsche stuff and OE (whatever that is?), the former is £781 incl vat and the latter 50% thereof. My thinking goes along the following lines...............If I get an indie to do the work they will use OE parts rather than Porsche and their labour rate will be likely lower. My bill will be circa £600 less as advised by Black80xa above, and I like the sound of that. However I am then in the position of having non Porsche original parts on the car. If I decide to trade the car into an OPC for another Porsche, what impact will the non Porsche parts have on the trade in price? Will they examine it that closely? Will they care, well they should if they would put it on the forecourt for sale as an original Porsche with a warrenty? Car is a May 06 Cayman S, 25k. Say I looked to trade it next spring approaching 5 years old with about 30k, will an OPC keep it for resale or trade in on? Time to get a quote from an indie for the work with original Porsche parts and without and compare with the OPC with the club discount factored in.

 

[Black80XSA]

OE quality items are supposely to the same spec as Porsche branded ones. Textar brake pads have the same part numbers ont hema s the Porsche ones, but don't have Porsche on their backs and don't come in Porsche branded boxes. Discs have traditonally been Sebro (grey painted hubs as per Porsche), or Zimmermann (non painted hubs), although Pagid seem to be appearing ont he eurocarparts site now also as OE quality. Who knows who supplies Porsche - i've not seen any definitive answer. All you can conclude fromt he internet is those that have used textar pads and Sebro/Zimmermann discs say they have felt/seen no discernable differences to Porsche branded items. They all rust equally lol!!. There was some discussion when Porsche inproved their extended warranty terms, that even if you had recent Porsche brakes fitted and Porsche had no record of an OPC changing them, they would refuse the warranty extension. Perhaps extreme overkill, and maybe there is some more clarification on this now, but certainly 15 months ago it was debated. Would they pick up Sebro discs and textar pads on a 111-point inspection? No idea, but i bet there's some variability from OPC to OPC on their vigilence. I think Richard put a document somewhere on brake disc thicknesses - couldn't find it in the 996 technical articles, but this is a useful website for changing pads/discs [link=http://www.bombaydigital.com/boxster/projects/brakes/change_pads/]http://www.bombaydigital.com/boxster/projects/brakes/change_pads/[/link] [link=http://www.bombaydigital.com/boxster/projects/brakes/change_rotors/]http://www.bombaydigital.com/boxster/projects/brakes/change_rotors/[/link]

 

[Black80XSA]

This was Richards post for the 996 cars, which are in most cases the same as the Boxster/Cayman [link=http://www.porscheclubgbforum.com/tm.asp?m=229522&mpage=1&key=thickness&#229830]http://www.porscheclubgbforum.com/tm.asp?m=229522&mpage=1&key=thickness&#229830[/link]

 

[Nick_USA]

One thing not mentioned is never re-use the calliper bolts. These should always be replaced after they have been undone.

 

[sawood12]

Concentric rings/grooves on the disc face are not an issue. This is due to the way pads are manufactured - basically by taking fine metal powder and compressing it into shape under extreme pressure which effectively welds the metal particles together. Due to this you can get random variations of the density of powder throughout the material which can cause the grooving in the discs when a small hard clump of pad material cuts a groove, and once a groove is cut it will wear at the same rate as the rest of the disc so even when the clump of pad material has worn away the groove will still remain as the pad takes up its shape. It is of no detrimental effect to the braking performance and shouldn't be the reason for discs being rejected. This is a generic effect with disc brakes - i've had it on every car i've ever had to varying degrees. They are often not as deep as they appear and are usually more of a ripple than a groove.

 

[bajers]

All interesting stuff and very informative chaps. Thanks for the links Black80XSA, I have saved these for future use. Personally, I think I am going to have a go myself and use OE quality parts. It sounds like Porsche sources one of the above manufacturers in any case and don't actually manufacture their own and these are no better or worse than standard Porsche kit. I am going to leave it until the spring though and let winter ravage the existing discs but would be very interested to see how you got on Pete with yours? On the extended warranty front, I will probably have a look at somewhere like 'Warranty Direct'. I am assuming it will be cheaper than the silly prices I have been given by Porsche and I dont intend selling the car for a while yet, so it will not be a selling point of 'full Porsche warranty' because it will have probably expired when it comes to selling in any case. Any thoughts or knowledge on independant warranty companies please? Think it's pretty poor on Porsche only offering 2 years as standard as some of the cheapie Oriental offerings are coming with 5 or even 7 years now. Not sure if Vauxhall might be offering lifetime warranty for the 1st owner!! Really like the forum though guys and it seems all I have done up to now is slag Porsche off. Not meaning to really because I really, really love everything about the car (even the brakes). Hope you get sorted soon Peter. Cheers. Barry.

 

[Christoff]

A 111 point check WILL pick up on non genuine items and they will notice anything that isn't how it's supposed to be IMO a 3rd party warranty isn't worth the paper it's printed on. Porsches warranties cover a lot of things and customer services / goodwill are very helpful.

 

[spyderman]

Lots of stuff regarding third party warranties on BoXa.net. I recently had a quote from Warranty Direct and it's not actually much less than Porsche - but would allow non-Porsche servicing. Don't go by their online quotes, though.

 

[Peter Anthony]

Well Guys, I had the brake fluid changed today and I do feel an improvement in brake travel. It may just be subjective, but it is as I call it. Cost was £150. By chance I came across an invoice from 20th October 2007 when I had my Boxster S brake fluid changed, it was £121. I don't imagine a Cayman S uses more fluid or is a more time consuming car to work on so inflation at a Porsche is running quite high. While I was there I asked for a detailed quote for the fronts and rear discs and pads etc to be changed. I mentioned the 10% discount on parts as a club member and was pleased to be told they gave 10% on labour as well. I was given the quote below which may be of interest to you. They also confirmed they change all the other bits and pieces which is good news. As discussed, please find a quote below to replace your front and rear brake discs and pads. The quotes include discs, pads, warning wires, caliper bolts, fitting kits and brake pad shims. A 10% parts discount has been applied and the labour is @ £99.00 per hour. Front - £727.94 inc VAT Rear - £644.59 inc VAT This is a total saving of £205.38 inc VAT. I understand the normal labour rate is £120 per hour. They will hold the quote for six months. Not sure if the service assistant was aware of the imminent 2.5% vat rise on the way though! As I am feeling better about the brake feel now I think I will leave it through the winter and reassess in the Spring. Important point is the brakes do work well and pull the car up. Does anyone know what % wear constitutes worn out? The workshop chap said the pads had about 35% to 40% left. I am showing my ignorance but I guess the pads have a sensor wire embedded somewhere close to the wear out % as a warning, but where is that likely to be? I have read on the forum a number of times of pressure from OPCs to change the discs which set the warning bells going with me, however I must be fair to the Service Manager on Tuesday and the Assistant today, they pointed out the state of the discs and gave their advice, no more, no pressure. I would also say I have had nothing but very good service from Cambridge OPC during my visits. Mind you they can take money off you faster than a Porsche 0-62 time! Coffee is good as well.

 

[uknick]

How much wear before you change the pads? I have just had mine changed at an OPC before the wear sensors were activated. The OPC still changed the sensors (£22 + vat each) , so in future I will wait until the sensors tell me to change the pads.

 

[bajers]

It sounds like you were treated well by your dealer Peter and the discount takes a bit of the sting out of the tail. Good news about the fluid change improving things as well. Did they say what the thicknes of your discs and pads were? I have had all the wheels off my car to-day and had a good measure and if 22mm/18mm is minimum thickness, I am in serious,serious bother. Just using a steel rule laid against the discs and not sure if this is the right way to do it, but it looks like mine are 17mm front and 13mm rear! They do look mighty thin... Pads look about 8mm front and 5mm back. I don't think I can afford to wait for the spring now to do mine and I suppose I should be having a polite chat with the dealer seeing as I only bought it last week. Another interesting point I noted to-day whilst poking around. The callipers are Brembo, arguably one of the best brake manufacturers in the world. I would have thought Porsche would have put the Brembo logo on them like Nissan, Subaru, et-al, rather than just putting the Porsche sticker on them. Just an observation really. Replacing the discs/pads doesn't look at all bad though. The two calliper bolts are the Torx type heads and once you have got the wheel off, the only thing holding the discs on are two Philips head countersunk screws. The wear sensors are pretty straightforward and the pads are held in by a single pin held by a spring clip. Noted the web link instructions about using an impact driver on the screws. Sounds like it is safer to use OE Porsche bits though if I want to go for a Porsche warranty next year, but they were talking 800 odd pounds for this plus the inspection check. Why don't they offer 3 years as standard??? Poor show Porsche! Wonder if the kids would appreciate the old discs and pads for Christmas prezzies this year as I won't be able to afford much else!