996 TT Caliper Woes!
Discussion
andys2 said:
Most engineering suppliers only carry metric fine M12x1.25 or metric coarse M12x1.75. The Porsche bolts are M12x1.5 and I've yet to find anybody who can supply these.
The last ones I got came from a breaker, I paid £10 for 8, he told me that they were about £3ea from Porsche.
Porsche don't make these components themselves but use 3rd party suppliers for most of their components. They must be available from another source with a bit of research.
Edited to add these links which list M12x1.5 bolts, an further enquiry may bring up exactly what's needed:
www.performancealloys.com/nuts_bolts.asp
www.priracing.co.uk/product.php?xProd=698
www.kml-bearing.com/public/public_new/pub_03/pub_0301/WHEEL-HUB-BEARING-UNITS/Ball-bearing-type.htm
>> Edited by silver993tt on Thursday 3rd November 10:00
silver993tt said:
Porsche don't make these components themselves but use 3rd party suppliers for most of their components. They must be available from another source with a bit of research.
Edited to add these links which list M12x1.5 bolts, an further enquiry may bring up exactly what's needed:
www.performancealloys.com/nuts_bolts.asp
www.priracing.co.uk/product.php?xProd=698
www.kml-bearing.com/public/public_new/pub_03/pub_0301/WHEEL-HUB-BEARING-UNITS/Ball-bearing-type.htm
Errr, very interesting links but we are talking about calliper bolts here - yes they are 12mmx1.5 pitch but have a smallish allen key head, not a whopping great nut on the end.
Leave the OPC alone.... they have to make a profit after all....
gfreeman said:
Porsche don't make these components themselves but use 3rd party suppliers for most of their components. They must be available from another source with a bit of research.
Edited to add these links which list M12x1.5 bolts, an further enquiry may bring up exactly what's needed:
www.performancealloys.com/nuts_bolts.asp
www.priracing.co.uk/product.php?xProd=698
www.kml-bearing.com/public/public_new/pub_03/pub_0301/WHEEL-HUB-BEARING-UNITS/Ball-bearing-type.htm
Errr, very interesting links but we are talking about calliper bolts here - yes they are 12mmx1.5 pitch but have a smallish allen key head, not a whopping great nut on the end.
er....yes but as I posted, a further enquiry may lead to the correct component.
gfreeman said:
Leave the OPC alone.... they have to make a profit after all....
Ok then do you pay list price for everything you buy 'because the companies have to make a profit after all'? I also need to minimise the loss from my bank account so I will look for the lowest cost for the same item
I don't mind paying a price for something that I know I can't get somewhere else and that I know has cost the supplier time & effort to produce. However, Porsche do not produce these individual components. They are acting as a 3rd party adding very little value.
Would you buy tyres for your Porsche from a an OPC? I and many others certainly wouldn't
there is no possible way the brakes can exert enough force on even 1 bolt to shear it, the tyre grip being the limiting factor, unless you're accelerating at the same time (4wd). and overtightening is gonna wreck the alloy well before the bolt. imo the only way for it to shear is for the bolts to be loose allowing the caliper to hit the wheel, which seems like enough force and the loose bolts will allow some leverage so forces not just in shear direction but tension too... i'd guess they wern't torqued enough...
After investigation - Apparently the bolts used were the "Green" coloured ones (72mm long) and it should have had "black" coloured ones (77mm long) and so they have pulled out of the hub.
What is strange is the car had a new caliper fitted by OPC in March 04 (The one which came off !)and the invoice part nos are for the 77mm bolt.
What is really strange is that the car has not had the caliper taken off since then and has only been in OPC for servicing.
The Car had new brake pads fitted by SCOM but I was there whilst they were fitted and the calipers were NOT removed!
I am now faced with a huge bill and cannot understand how the wrong bolts have been fitted ( They are wrong on both front calipers)
What is strange is the car had a new caliper fitted by OPC in March 04 (The one which came off !)and the invoice part nos are for the 77mm bolt.
What is really strange is that the car has not had the caliper taken off since then and has only been in OPC for servicing.
The Car had new brake pads fitted by SCOM but I was there whilst they were fitted and the calipers were NOT removed!
I am now faced with a huge bill and cannot understand how the wrong bolts have been fitted ( They are wrong on both front calipers)
jj996 said:
After investigation - Apparently the bolts used were the "Green" coloured ones (72mm long) and it should have had "black" coloured ones (77mm long) and so they have pulled out of the hub.
What is strange is the car had a new caliper fitted by OPC in March 04 (The one which came off !)and the invoice part nos are for the 77mm bolt.
What is really strange is that the car has not had the caliper taken off since then and has only been in OPC for servicing.
The Car had new brake pads fitted by SCOM but I was there whilst they were fitted and the calipers were NOT removed!
I am now faced with a huge bill and cannot understand how the wrong bolts have been fitted ( They are wrong on both front calipers)
I think you need to be asking the OPC how the situation occured
Try someone like www.heads.co.uk for these bolts.
If not, most decent engineering companies will be able to supply them. Porsche calipers and hubs are supplied pre-assembled by Brembo and the caliper is used on various cars and brake kits. Someone like AP (a Brembo company) will have these bolts in stock.
If not, most decent engineering companies will be able to supply them. Porsche calipers and hubs are supplied pre-assembled by Brembo and the caliper is used on various cars and brake kits. Someone like AP (a Brembo company) will have these bolts in stock.
Not sure what the 'black' coloured bolts are.
I changed the front disks on my TT a couple of weeks ago myself using original equipment disks from independent part suppliers (911 Design) but had to purchase the 'green' stretch caliper bolts from the local OPC.
As an fyi, the disks are incredibly easy to change/fit - had both sides fitted in less than an hour- reminded me about my first car when when I couldn't afford to put it into a gagage to be fixed and had to do all the work on it mysef - time hasn't changed things for me !!
>> Edited by toby tucker on Saturday 5th November 10:40
I changed the front disks on my TT a couple of weeks ago myself using original equipment disks from independent part suppliers (911 Design) but had to purchase the 'green' stretch caliper bolts from the local OPC.
As an fyi, the disks are incredibly easy to change/fit - had both sides fitted in less than an hour- reminded me about my first car when when I couldn't afford to put it into a gagage to be fixed and had to do all the work on it mysef - time hasn't changed things for me !!
>> Edited by toby tucker on Saturday 5th November 10:40
toby tucker said:
Not sure what the 'black' coloured bolts are.
I changed the front disks on my TT a couple of weeks ago myself using original equipment disks from independent part suppliers (911 Design) but had to purchase the 'green' stretch caliper bolts from the local OPC.
As an fyi, the disks are incredibly easy to change/fit - had both sides fitted in less than an hour- reminded me about my first car when when I couldn't afford to put it into a gagage to be fixed and had to do all the work on it mysef - time hasn't changed things for me !!
>> Edited by toby tucker on Saturday 5th November 10:40
What part number are the green stretch bolts? and what length are they? If they are 72mm long then go for the 77mm long ones and also make sure they are at the correct torque.
My car is capable of over 200mph and I really dread to think what might have happened if my caliper had fallen off at those speeds - I don't think I would have been writing on this forum now!! The worst thing other than having to pay for repairs is being called "Forest Gump" cos he had calipers which failed! Good friends I have!!
silver993tt said:
Porsche don't make these components themselves but use 3rd party suppliers for most of their components. They must be available from another source with a bit of research.
Edited to add these links which list M12x1.5 bolts, an further enquiry may bring up exactly what's needed:
www.performancealloys.com/nuts_bolts.asp
www.priracing.co.uk/product.php?xProd=698
www.kml-bearing.com/public/public_new/pub_03/pub_0301/WHEEL-HUB-BEARING-UNITS/Ball-bearing-type.htm
Errr, very interesting links but we are talking about calliper bolts here - yes they are 12mmx1.5 pitch but have a smallish allen key head, not a whopping great nut on the end.
er....yes but as I posted, a further enquiry may lead to the correct component.
gfreeman said:
Leave the OPC alone.... they have to make a profit after all....
Ok then do you pay list price for everything you buy 'because the companies have to make a profit after all'? I also need to minimise the loss from my bank account so I will look for the lowest cost for the same item
I don't mind paying a price for something that I know I can't get somewhere else and that I know has cost the supplier time & effort to produce. However, Porsche do not produce these individual components. They are acting as a 3rd party adding very little value.
Would you buy tyres for your Porsche from a an OPC? I and many others certainly wouldn't
Sorry if I offended you, I was attempting irony......
And these are NOT stretch bolts everyone.... Apparently you only have to replace them cos they are coated with an anti- corrosion treatment. A hell of a lot of people make do with a dollop of loctite instead because they are very strong bolts and overpriced.
The only reason I bought a set is that I am changing to 6 pots and Alcons and decided to give em a treat - so new dust seals, anti squeal shims, RS 29's and calliper bolts. Yes I know the seals will last about 10 mins and the discs rattle and the pads squeal despite the shims which can be left out... I just thought I'd start with a clean sheet.
And back to the original thread, I think I would be back down the dealers with my angry head on. If as you say no-one else has touched it then clearly the bolts were not tightened. That is the one and only way they would get sheared off (after being clumped by the wheel, most probably).
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