Is my OPC pulling a fast one?? - Page 1 - Porsche General - PistonHeads UK

Morning all, I’ve just checked my Panamera Turbo in for a service after buying it from Porsche in Jan / Feb this year. I actually sold them the car back in September last year and bought it back for a fair bit less than they gave me. This service was thrown in as part of my purchase because we all knew it was coming up. Before I bought the car back, I wanted to get some comfort on the condition of the rear brakes (I did the front disks and pads around 6k miles ago) and I was told the pads had 6mm left and the disks had over 50% life left in them. I’ve got all this in writing from the sales team and also the service team. I’ve just had the condition report and the disks are actually showing as being 0.9mm off max wear and are very corroded (the car hasn’t moved much for the last two months due to a big leg injury). The pads are also worn and in recent driving the wear indicator has come on. Apparently this is down to corrosion from the disk cutting into the sensor on the pads. I’m dubious about this; I’ve done under 1,500 miles since I bought the car back and after around 8 weeks of minimal usage, surely the brakes shouldn’t be irreversibly corroded. Also, the vehicle check showing the disks being 0.9mm off max wear is not consistent with the emails telling me the disks have over 50% life in them. Has anyone had anything similar? The service advisor (who I always find excellent) is pinning this on the lack of use but it seems like mis-selling to me. Any recommendations gladly received! Edited by Mosdef on Tuesday 13th June 08:42

Thank you, I’m coming round to a similar view, albeit I can’t do the work myself. They’ve said they’ll look into a discount, which would be a bonus. I’ve no doubt the disks are corroded and I know that can cause issues but they clearly weren’t in the shape they told me they were at the time of sale. I’ll look to do disks and pads at the same time regardless.

If you have doubts then just get the car back and take a look at the discs yourself or take it to a garage you do trust. Presumably you don't have PCCBs on the car?

Thank you, I saw the video they sent over and they’re definitely not in the best shape but I’m not an expert, far from it. I don’t have PCCBs - I wish I did!

If you can get to the garage, turn up unannounced and request they measure them in front of you and then show you the service manual specifications?

Mosdef said: Also, the vehicle check showing the disks being 0.9mm off max wear is not consistent with the emails telling me the disks have over 50% life in them. You/they are using two different ways of communicating wear. If the disks from new have 1.8mm of wear, then 0.9mm left is 50% life left. You need to know either how much wear is allowed from new, or what 0.9mm of wear left is in terms of a percentage of wear from new.

jeremyc said: ou/they are using two different ways of communicating wear. If the disks from new have 1.8mm of wear, then 0.9mm left is 50% life left. You need to know either how much wear is allowed from new, or what 0.9mm of wear left is in terms of a percentage of wear from new. You’re absolutely right, I think the discs have 1.8mm of new based on the reading of the front set. Watching the video again, it’s the corrosion and the lip(s) that seems to be the issue.

Mosdef said: the disks are actually showing as being 0.9mm off max wear Most manufacturers set their "max wear" level in routine servicing at a level where a car in average use will definitely make it to the next service without the discs getting worn to a level that's considered unsafe. What is unsafe? So thin that the disc overheats/fails or so thin that pads can be ejected from the callipers (unlikely). This is precisely why so many people complain about the 'discs and pads, Sir' situation. In your position I'd be tempted to clean up the discs by driving with the old pads for a while, then just DIY the pads. But that depends on the relative cost of discs, pads and labour for your car. Yes, discs can rust very fast. If you wash a car and leave it overnight then look at the discs with a torch it's quite likely rust may have started alreday. Often the parking pads will seize on if a car's put away with wet discs and you'll hear a bang next time it's taken out of the garage.

There is an issue with bleeding as well .Not saying it’s here btw . The problem with twin caliper ( I mean pistons on each side ) to bleed properly you need to crack open the inner as well as the obvious outer nipple .So in effect 2 x the work .A lot don’t do the inner .This means as the months + yrs roll by the inner pistons just loose efficiently and nearly pressure the pad and disk = inner corrosion. I know this from stepping in DIY ing my own brakes on Bentley GT s and Porsches ( various ) . Despite invoices to say brake fluid replacement the inner nipple has basically corroded fast . Talking steel nipple against alloy calliper body .+ sprinkle in U.K. road salt . If a tech uses gorilla tactics then they snap and it’s a awkward telephone conversation with the punter .Not being critical but this op ain’t gonna like a fresh set of callipers against the description of the SH is he ? Now that’s really something to come on here whinge about ! Amazed at the difference of colour of the fluid coming out between the inner and outer bleed nipples . With the inners I used penetrating fluid 3/4 per day for 3/4 days before getting a ring spanner on and them very carefully open them .Coffee colour fluid ! The outer just turns as you would expect if it was opened within 12 or 24 months . Once you get the inner pistons moving properly you don’t get this inner corrosion phenomenon. Think about it the disk is not made of two materials is it and the size and number of pots and the pipe age between inner / outer are identical, so same forces applied . Why would you design it all to 100-300 % increase pressure on the outer pistons relative to the inner any how .They don’t. Since diy ing this ,subsequent fluid refreshes the inner + outer colour of the discharged fluid are identical . If you don’t believe me try cracking open the nipples your self and use a pressure bleeder ( fresh fluid connected to the reservoir ) and see for your self . The techs are under so much pressure to clear jobs up and this skipping opening the inner is a easy cop out . Also back on topic cars with PASM wear out the rear brakes faster than fronts because even with normal to moderate driving the “system “ is constantly nipping up rear callipers ( well it’s trying with semi ceased inners ) as you round roundabouts etc .No don’t need to track it it acting all the time . Edited by Fiammetta on Tuesday 13th June 12:37

Fiammetta said: There is an issue with bleeding as well .Not saying it’s here btw . The problem with twin caliper ( I mean pistons on each side ) to bleed properly you need to crack open the inner as well as the obvious outer nipple .So in effect 2 x the work .A lot don’t do the inner .This means as the months + yrs roll by the inner pistons just loose efficiently and nearly pressure the pad and disk = inner corrosion. I know this from stepping in DIY ing my own brakes on Bentley GT s and Porsches ( various ) . Despite invoices to say brake fluid replacement the inner nipple has basically corroded fast . Talking steel nipple against alloy calliper body .+ sprinkle in U.K. road salt . If a tech uses gorilla tactics then they snap and it’s a awkward telephone conversation with the punter .Not being critical but this op ain’t gonna like a fresh set of callipers against the description of the SH is he ? Now that’s really something to come on here whinge about ! Amazed at the difference of colour of the fluid coming out between the inner and outer bleed nipples . With the inners I used penetrating fluid 3/4 per day for 3/4 days before getting a ring spanner on and them very carefully open them .Coffee colour fluid ! The outer just turns as you would expect if it was opened within 12 or 24 months . Once you get the inner pistons moving properly you don’t get this inner corrosion phenomenon. Think about it the disk is not made of two materials is it and the size and number of pots and the pipe age between inner / outer are identical, so same forces applied . Why would you design it all to 100-300 % increase pressure on the outer pistons relative to the inner any how .They don’t. Since diy ing this ,subsequent fluid refreshes the inner + outer colour of the discharged fluid are identical . If you don’t believe me try cracking open the nipples your self and use a pressure bleeder ( fresh fluid connected to the reservoir ) and see for your self . The techs are under so much pressure to clear jobs up and this skipping opening the inner is a easy cop out . Also back on topic cars with PASM wear out the rear brakes faster than fronts because even with normal to moderate driving the “system “ is constantly nipping up rear callipers ( well it’s trying with semi ceased inners ) as you round roundabouts etc .No don’t need to track it it acting all the time . Edited by Fiammetta on Tuesday 13th June 12:37 Time to worry is when the tech just bleeds from the outer nipple after the hard brake lines have been changed and forgets about the inner nipple as you will have no brakes. I can confirm this is very very scary!!

FMOB said: Time to worry is when the tech just bleeds from the outer nipple after the hard brake lines have been changed and forgets about the inner nipple as you will have no brakes. I can confirm this is very very scary!! Not porsche related, but the time to worry for me was when I repeated the mistake a previous "bodging bob" made by fitting a solid disc where a vented disc should have been fitted. (The rear of an omega 3.2 MV6) Finding this out because of smoke coming out of the rear wheel as you pull into a petrol station, in Buxton, to fill up before you are able to head over to Macclesfield. Why is my rear wheel on fire next to a petrol pump ? It's not? It's just very hot fluid being squirted out onto the pads that are trapped between disc and caliper. My biggest worry, was what else had been bodged. (Not much it turned out)

Fiammetta said: There is an issue with bleeding as well .Not saying it’s here btw . The problem with twin caliper ( I mean pistons on each side ) to bleed properly you need to crack open the inner as well as the obvious outer nipple .So in effect 2 x the work .A lot don’t do the inner .This means as the months + yrs roll by the inner pistons just loose efficiently and nearly pressure the pad and disk = inner corrosion. I had this very discussion with an OPC after being charged £150 for a fluid change...they never took the wheels off (less time less cost to them) max cost to me though, I took them to task about it and they lost a customer forever.

Klippie said: Fiammetta said: There is an issue with bleeding as well .Not saying it’s here btw . The problem with twin caliper ( I mean pistons on each side ) to bleed properly you need to crack open the inner as well as the obvious outer nipple .So in effect 2 x the work .A lot don’t do the inner .This means as the months + yrs roll by the inner pistons just loose efficiently and nearly pressure the pad and disk = inner corrosion. I had this very discussion with an OPC after being charged £150 for a fluid change...they never took the wheels off (less time less cost to them) max cost to me though, I took them to task about it and they lost a customer forever. The trouble I had I think is down them to getting used to doing the brake fluid change only for the outer bleed nipple, bit of group think going on as the brake bleeding always gets done on the outer and basically they forgot the inner bleed nipple exists. Cue serious problems and lives at risk when the learned method is applied when brake lines have been repaired and there is air in the system.

Thanks everyone for the comments, I ended up going for new discs and pads in the end. I got some more photos from the OPC and the pitting was pretty awful. I’m sure there might have been cheaper solutions but I’ll take the peace of mind and not having to fiddle around getting them skimmed etc elsewhere.