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997.2 GTS: Fun with Center Locks - Front Rotor/Pad Change
After taking delivery of my new-to-me GTS, I felt a fairly bad vibration at speed (60-70mph) when tapping the brakes. The previous owner tracked the car, and thus caused the issue via hot spots. Being fairly OCD and the fact that I plan to hit a few courses next year, I went ahead and ordered new front rotors/pads so I could start fresh and not have to change these at the beginning of next season.
I've always admired Center locks have been a fan due to their looks and motorsport heritage. Now that I'm officially an owner and invested in all the tools, well let's say I need a few more times with them before I really know how I feel. But, I'm beat after today!
No impact guns, oh and use something to prevent your clothes from getting soiled! I used moving boxes scattered about the garage and likely to my detriment. My knees are yelling at me right now...
Jacked and all 4 off the ground in preparation for bleeding after front rotor/pad change...
Precision instruments breaker bar/torque wrench combo set. The center lock tool is attached to the torque wrench and extension here, as this photo was taken after the work was completed and I was torquing the nuts.
Porsche manual indicates to raise the car to break the nuts. Yeah, that isn't happening, even after I pressurized the brakes and used a spreader to hold the brake pedal to the floor. I had to lower the car off all 4 jack stands, and break the nuts, then raise again... total buzzkill and wasted about an hour.
Wheels finally off, time to get to work.
Important step after removing center lock wheels is inspecting the hubs, threads, and locking mechanism.
good to see about ~10mm of Castrol Optimol grease on the centering hub, any less is a sign of something amiss...
Making sure the end of the hub isn't gouged, chipped, bent, and the threads are in good shape...
Removed the caliper, rotor, and secured the caliper up top using zip ties around a spring, and carful not to break/bend any brake lines...
Having a look at the naked hub and pulled out the locking mechanism in the next photo...
I found this to be the most fascinating part in the engineering of the center locks. It is a simple lightweight mechanism that fits snugly in the hub without any fasteners and is spring loaded into the center lock nut which prevents it from backing off. It's one of the of most important safety features!
Thing of beauty...
You must purchase rotor wheel guides anytime you replace a rotor on a CL car. In doing so, I found out that I didn't have a Torx-25 in my tool box!!!
Amazon Prime Now to the rescue. I ordered a multi-bit set for $20 and it was delivered within the hour (30 mins actually).
Now properly equipped, I was able to tighten the wheel guides. The back of these fit into the holes of the hub.
Fresh metal waiting to get in bed with, pads...
No pics of wheels and lugs going back on as I was in a hurry by this point. A few very important tips:
1- You have to apply liberal amount of Castrol Optimol TA paste to the conical surface of each center lug, as well as the threads. You need to make sure they are clean and free of debris. This video was very helpful for me:
2- I suggest getting the wheel alignment tool, especially for the rears since they are so wide. The tool helps you get the wheel on the hub without damaging the rotors or calipers.
3- Once you torque the lug, you need to back it off 60-90 degrees and re-torque it.
I hope these pics of the hubs and rotor assembly are helpful for anyone with CL contemplating doing a DIY brake job. It's not that difficult, just need some patience and maybe a few weeks of the gym prior to breaking the lugs!
Great to see the write up. As a center lock owner I to went through a lot of frustration at first. Now I crack pen the wheels with the car on the ground - all four. Then lift one side to do two wheels (only need to step on the brake for the front, rear works out with the parking brake fully engaged) then the other side. The paste is a mess to deal with. But all in all its not that different once you get the hang of it.
Two questions - I understand that the rotors are different for CL. I am looking to get slotted... Did you find any aftermarket rotors?
Two- what's the process to take out the red nipples? I could not figure that out just by looking at them (did not try much either).
Great to see the write up. As a center lock owner I to went through a lot of frustration at first. Now I crack pen the wheels with the car on the ground - all four. Then lift one side to do two wheels (only need to step on the brake for the front, rear works out with the parking brake fully engaged) then the other side. The paste is a mess to deal with. But all in all its not that different once you get the hang of it.
Two questions - I understand that the rotors are different for CL. I am looking to get slotted... Did you find any aftermarket rotors?
Two- what's the process to take out the red nipples? I could not figure that out just by looking at them (did not try much either).
Thanks
Didn't look for aftermarket rotors and wanted to stay stock. Porsche rotors are sufficient for my planned use; 75% street and 25% track.
You're supposed to use new "nipples" with new rotors. You simply sandwich the rotor with the nipple on front and retainer in back, then tighten the T25 torx screw.
FYI, people rarely actually "warp" rotors, and is a very common misconseption. the vast majority of the time it is uneven brake pad material. So since you already have the new ones, do NOT throw away the old ones, they aren't "bad".
FYI, people rarely actually "warp" rotors, and is a very common misconseption. the vast majority of the time it is uneven brake pad material. So since you already have the new ones, do NOT throw away the old ones, they aren't "bad".
THIS! Seneca and I had a chat and I made the same point. The originals were worn but would make good track rotors for a couple days on Pagids, PFC, etc. They just needed to be rebedded using a proper bedding technique. IMO, they'd be good to go with a more aggressive pad compound after a couple of warmup laps to bed again.
You must purchase rotor wheel guides anytime you replace a rotor on a CL car. In doing so, I found out that I didn't have a Torx-25 in my tool box!!!
Does anyone know why it’s necessary to replace the rotor wheel guides/red nipples (wheel locating pins) on the rotors every time rotors are replaced? At about $200/wheel, it seems a bit excessive for a throwaway part. I would love to know the reasoning behind not reusing these.
I have center-locks on my 2011 GTS. First of all, the rotors for a Carrera S fit perfectly. The wheel guides can be reused as long as they aren't damaged. Very easy to transfer the wheel guides to the new rotors. The brake pads are identical. You need a special breaker bar for removal and a high quality torque wrench that will accommodate 444 ft/lbs. The rear wheels can be torqued off the ground but the fronts must be on the ground. I highly recommend the delrin wheel guide that can be purchased from Reenlister SmokinGTS. Hope this simplifies the center-lock mystery. Just be sure that the center locking device is engaged A small screwdriver will do the trick.
I have center-locks on my 2011 GTS. First of all, the rotors for a Carrera S fit perfectly. The wheel guides can be reused as long as they aren't damaged. Very easy to transfer the wheel guides to the new rotors. The brake pads are identical. You need a special breaker bar for removal and a high quality torque wrench that will accommodate 444 ft/lbs. The rear wheels can be torqued off the ground but the fronts must be on the ground. I highly recommend the delrin wheel guide that can be purchased from Reenlister SmokinGTS. Hope this simplifies the center-lock mystery. Just be sure that the center locking device is engaged A small screwdriver will do the trick.
lurchphil, thanks for the response. So you don’t have to buy rotors made for center locks? I noticed that some of the vendors sell them specifically for the center lock models and the part #’s are different. And if the wheel guides can be re-used if not damaged, what does a damaged one look like?
10-20-2016, 02:26 AM
997.2 GTS: Fun with Center Locks - Front Rotor/Pad Change
