PCCB Rotor Replacement Options
06-01-2023, 02:18 PM
#16
RL Community Team
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The 958 calipers used with the 410mm rotors mount radially through the top surface whereas the 957 calipers mount axially through the side.
I looked through my measurement photos and the top radial bolt spacing is different by 3 or 4 mm.
What I don't have measurements of is whether the rotor offset is different as I didn't need that info to have my adapters made, so don't know if you could just separate and space out the radial top portion of the 957 caliper from the axial mounting portion. You wouldn't have the optimal pad to rotor swept area but it might work.
I looked through my measurement photos and the top radial bolt spacing is different by 3 or 4 mm.
What I don't have measurements of is whether the rotor offset is different as I didn't need that info to have my adapters made, so don't know if you could just separate and space out the radial top portion of the 957 caliper from the axial mounting portion. You wouldn't have the optimal pad to rotor swept area but it might work.
06-01-2023, 02:33 PM
#17
As per Champion Porsche (dealer in Florida) and the local dealer, the 410mm discs have their unique caliper size and mounting position which require a series of different parts than the 390mm version, among them, the knuckle.
As stated earlier, I'm not a mechanic, nor pretend to be one. I'm only sharing information that I've obtained after many hours of research and multiple confirmations.
Perhaps @Petza914 may have more detailed information as he adapted 958 series 410mm sized rotors to his 957 CTTS (which in theory uses the standard 390mm rotors and calipers). There is an entire thread dedicated to the modifications he had to go through to make this work. I do understand that in his case we are mixing different series of Cayennes, but it confirms that the calipers between 390 and 410 are in fact different and are not directly interchangeable.
As stated earlier, I'm not a mechanic, nor pretend to be one. I'm only sharing information that I've obtained after many hours of research and multiple confirmations.
Perhaps @Petza914 may have more detailed information as he adapted 958 series 410mm sized rotors to his 957 CTTS (which in theory uses the standard 390mm rotors and calipers). There is an entire thread dedicated to the modifications he had to go through to make this work. I do understand that in his case we are mixing different series of Cayennes, but it confirms that the calipers between 390 and 410 are in fact different and are not directly interchangeable.
If you look at the porsche parts catalog, there's only 2 part for the steering knuckle, left vs right. https://parts.porschechandler.com/v-...ion-components
If the 410mm on the 958 requires a different part, can the dealer provide part numbers for everything that needs to be changed?
06-01-2023, 03:39 PM
#18
I have not done the research to "downgrade" a 958 that was originally equipped with 410mm fronts to a 390mm, but both dealers that I spoke to told me "it's a lot of hassle and expense, might as well pay what the 410s cost to replace". Spending $30 on replacing all 4 rotors (of which the fronts are 410mm) and pads is not an option as far as I'm concerned when the entire vehicle is worth, at most, $25K (local prices). A CTT of the same vintage and condition (hard to find, but possible if you wait long enough) with iron rotors would be worth the same (used) and perhaps sell quicker as it doesn't have that "potential $30K bill". Again, this applies to local market, not sure if the same applies to USA, but my logic says it would.
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06-01-2023, 07:21 PM
#20
Sure could sound that way…. They wanted me to trust them that the discs are OK and I shouldn’t have any issues (think leap of faith…) Well, today I spoke to yet another person within the organization and made it very clear to him what my position is and all of the research I’ve done to which he responded by agreeing to in fact providing me with the measurements I had asked for last week. Now to wait and see how long it will take them to do so. According to this manager, of all the PCCB equipped vehicles they have sold (relatively few in comparison to USA figures), they have yet to replace any PCCB discs and have only replaced two or three sets of brake pads (one of them is on a 991 GT3 that sees track days once in a while).
01-10-2024, 02:18 PM
#21
Gus, I have been following your research on PCCB replacement options on Cayennes. Did you ever come across anybody who has actually replace PCCBs on a Cayenne? If so, anybody make the switch to steel? I am wondering if the PCCBs do last the life of the cars since I have not found any posts about it...but there are a lot of threads I have missed.
Cheers!
Cheers!
01-10-2024, 02:28 PM
#22
To the best of my knowledge, I have yet to get any kind of confirmation that anyone has done this: change from PCCB to iron/steel. Keep in mind that there are two sizes of PCCB rotors for our vehicles... that said, no, still no news from anyone that has confirmed doing this procedure.
I know many praises have been said about how great this (PCCB) brake system is and some, not all, have had great lifetime experiences, but at the end of the day, it's an option that will eventually require replacement, like many other things on our vehicles, it's just that the replacement of those rotors vastly surpass the total market price for the vehicle. Heck, I ended up with a "measly GTS" (non Turbo sized brakes), and I have yet to find a situation where I've said to myself "if only I had better brakes".
I know many praises have been said about how great this (PCCB) brake system is and some, not all, have had great lifetime experiences, but at the end of the day, it's an option that will eventually require replacement, like many other things on our vehicles, it's just that the replacement of those rotors vastly surpass the total market price for the vehicle. Heck, I ended up with a "measly GTS" (non Turbo sized brakes), and I have yet to find a situation where I've said to myself "if only I had better brakes".
01-10-2024, 02:32 PM
#23
Congrats on your GTS! I agree about not needing the braking power, it is just that I have several times found Cayennes with all the options I want...and the car happens to also have PCCBs. If we crowd fund we could get somebody to buy a cheap, high mileage Cayenne with PCCBs and see how long they last. Here is one with 115,000 mi and PCCBs for a measly $17k:
https://www.cargurus.com/Cars/invent...375397941/NONE
https://www.cargurus.com/Cars/invent...375397941/NONE
01-10-2024, 02:48 PM
#24
Now find the price of a similar Turbo, only difference being the brakes... Then, calculate the operating costs of said alternative ($2K brake job vs. $30K brake job) and see which one "wins". That is the "reasoning behind my madness"....
01-10-2024, 02:55 PM
#25
Rennlist Member
Congrats on your GTS! I agree about not needing the braking power, it is just that I have several times found Cayennes with all the options I want...and the car happens to also have PCCBs. If we crowd fund we could get somebody to buy a cheap, high mileage Cayenne with PCCBs and see how long they last. Here is one with 115,000 mi and PCCBs for a measly $17k:
https://www.cargurus.com/Cars/invent...375397941/NONE
https://www.cargurus.com/Cars/invent...375397941/NONE