spooltime

I knew my front brake rotors were already worn past their specified minimum thickness, but I was holding off on replacement until the pads wore down enough to illuminate the pad wear sensor. That happened last week, so it was time to tackle the job this past weekend.

This isn't a DIY, because there are already plenty of excellent ones already out there.

Here's a shot of caliper with the pin securing bolt removed and the pin partially removed. You can see in this picture how little friction material remains on the pads:

Attachment 1237526

Here's a shot showing the lip that had been carved into the old disc. Easily 2-3mm:

Attachment 1237527

The factory replacement discs for the larger brakes on the Turbo S are both expensive and heavy. Surprisingly heavy:

Attachment 1237528

The massive new brake disc mounted in place:

Attachment 1237529

And the final result, with the caliper cleaned-up a bit and everything re-installed.

Attachment 1237530

I chose to replace all of the related bits, including new caliper bolts, a new hardware kit for the caliper that includes new springs, new pins and new pin securing bolts, and well as installing new wear sensors. After bedding the pads in, the brakes feel just perfect.

bigbuzuki

That front brake setup is impressive.

hahnmgh63

Mine will probably be due this fall. Are the Pins the same as a regular Turbos or do you have the part numbers? I have new Rotors, caliper bolts, and the spring loaded keepers that the Pins hold in place but you probably have a good idea in that you should do the pins, at least every other pad change.

clubracer6

Anything unusual about the job? Where did you get the parts from and roughly how much? Nice pics, mine are due soon as well.

loxxrider

Ecstuning has nice kits available for this job.

spooltime

The pins are different, being slightly longer.

Here are the part numbers I used:

brake disc - L 955 351 401 61 (1 req.)

brake disc - R 955 351 402 61 (1 req.)

pad mounting kit 955 351 959 50 (this includes the two pins, two springs, and two locking bolts) (1 req.)

retaining bolt for discs to hubs N 910 282 02 (2 req.)

caliper mounting bolts N 906 854 03 (4 req.)

brake pads 955 351 939 50 (1 req.)

pad sensor 955 612 365 50 (2 req.)


Here are a few more pictures. The first is a front view of the caliper following install, showing all of the new hardware bits and pieces:

Attachment 1237534

Here's a better shot showing how over 90,000 miles of wear will carve out the disc:

Attachment 1237535

The minimum disc thickness permitted:

Attachment 1237536

What my discs were worn down to:

Attachment 1237537

Clearly, my front discs were shot, but because they are so thick to begin with, I believed I could wear them a bit past the minimum specified thickness. It's pretty easy to monitor wear with the digital thickness gauge.

And finally, here are the factory torque values for the various fasteners involved in the front disc R&R:

Attachment 1237538

spooltime

Nothing unusual. Just a minor PITA detaching the bracket holding the brake lines in place. Leave it to Porsche to use two different fasteners to secure the bracket - a T30 torx and a 6mm allen.

I sourced most of my parts from parts.com; the discs are the big tickets items. I stuck with stock pads because they work so well. The only aftermarket parts I used were the wear sensors, which I sourced from AutohausAZ. I always advise shopping around for prices for the really expensive items, in this case, the discs.

hahnmgh63

Nice write-up the Torque specs & part numbers. Yep, they were ready for a change.

Rob VN

Thanks for posting the torque values. Hopefully I have some time before the car needs this job done.

BlazinPond

Great pics and explanation of process/specs!
Thanks.

ubermich

In case you were interested in why they are so expensive and so heavy:


The labor and time that goes into each rotor absolutely astounds me.

spooltime

Since I did my rear brakes yesterday, I thought I'd close the loop here by supplying some more part numbers and related pictures. Again, this isn't a DIY since there are already many excellent ones out there that made this a very easy DIY job.

The minimum rear disc thickness permitted is 26mm. My old discs were original to the vehicle and had worn down to below the minimum:

Attachment 1237539

Once again, I replaced all of the related hardware, including all fasteners and the brake pad mounting parts (springs, pins, cotter pins) and new wear sensors as well. Here's a shot of the finished install:

Attachment 1237540

Overall, it seemed like the rear discs were much easier to do than the fronts, but maybe that was because having just done the fronts, there was much more familiarity with what needed to be done.

To do the rear brakes on a Turbo, you'll need the following parts:

95535240130 brake discs (2 req.)

95535293950 rear brake pads (1 req.)

N10555602 caliper mounting bolts (4 req.)

N91028202 fit bolts to attach disc to hub (2 req.)

N91038002 screw plugs for disc tensioner adjuster window (2 req.)

95535296000 brake pad hardware kit - springs, pins, etc. (1 req.)

95561236530 pad wear sensors (2 req.)

It's great knowing the beast has new discs and pads at all four corners, and it's definitely a worthwhile DIY project where you end up knowing all of the details have been attended to correctly.

spooltime

Interesting video, even though the 955 Turbo S uses 2 piece cast iron discs, not carbon fiber. What I wish though, was that Porsche sold replacement discs only and related hardware kits for the front discs, since it seems like such a waste to throw the disc hats away. Probably would save several hundred bucks, too, when disc replacement is necessary.

porschefan931

I always wondered this too, surely as a 2 piece set it would be possible to just sell the ring and reuse the Hat. I assume it would take extra labour time at the dealer and so they prefer to go with the a whole unit replacement.

spooltime

I had front and rear Brembo GT brake kits on my prior vehicle and did do front and rear disc replacements using new Brembo discs and the related hardware kits. It does require additional labor that probably isn't the best use of a dealer's tech's time, but for a DIY'er, I still wish we'd have the option of just replacing the discs since it would save some money.

While I'm writing this, I'm wondering why I didn't save the hats from my old discs to send out and see if it's possible to source replacement discs.