964 Brake Rotor Project Photos -Long and Bandwith Intensive!

[304065]

I recently bought a C2 Cabriolet which had warped front rotors. The symptoms were a pulsation in the brake pedal and a vibration of the steering wheel under braking at low to moderate speeds. A check of the service history (not a very tall stack of papers considering that she only has 35K on the clock) indicated that the front rotors had been turned before, and so another turning would not only take them close to the wear limit, but would further reduce their mass, making them even more prone to warping. New brake rotors for a 964 are surprisingly cheap, anywhere from $75-100 from the usual suspects, this board included. They look like this:



Hence, with new rotors in hand I started on a project SO EASY I would recommend it to anybody who can successfully execute an oil change! Here goes.

What you need:
Torque wrench (I used 1/2 Drive STAHLWILLIE)
19mm Socket
10mm Socket
Impact Driver
Hammer
Zip-Ties
Wire Cutters
Can of Brake Parts Cleaner
Beer (preferably BECK's)

1. Break lug nut torque on both front wheels.

2. Jack and properly support the front end. The 964 doesn't have a jack plate receiver in the rocker like the earlier cars, but there is a nice hard point at the forward end of the rocker. Remove the front wheels, revealing the front struts/brakes.



3. The first disassembly step is removing the caliper. It is held on by two 19mm bolts that pass through the mounting ears into the hub. With the bolts removed, the caliper should slide off the rotor with a little coaxing. Once you get it off, zip-tie it to the coil spring so that it is suspended by the zip-tie, NOT the brake lines.

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4. Once the caliper is clear, you can remove the rotor. The rotor is held to the hub by two Philipps-head screws. I suppose you could use a screwdriver to remove them, but I chose to use an impact driver. A couple whacks with a hammer and the screws were free, much easier than I expected.



5. As soon as the screws are removed, the rotor can be removed from the hub. This is a MAJOR time and hassle-saving design feature: some cars require removal of the hub from the spindle to remove the rotor, which can be greasy and requires more hassle in re-torquing the nut so the bearing doesn't run too tight. Once the rotor was off, I shot the whole assembly with brake parts cleaner and wiped it down.



6. Optional Step: I REMOVED the stone shield from the hub carrier- this is the piece of sheet metal you see in the above photo. My view is this inhibits proper circulation of air to the rotor contributing to high brake temperatures. There are three 10mm bolts that hold the shield on. Save them for the concours. . .

7. We're almost done. The new rotor goes on. The only trick here is getting the two countersunk holes in the rotor lined up with the holes in the hub, so you can reinstall the screws. Some racers omit this step: the rotor is sandwiched between the hub and the wheel and isn't going anywhere. I chose to reinstall the screws.

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8. Now it's time to reattach the caliper. You will find that the pads are too close together to get the caliper to fit over the rotor. So, I put the handle of my hammer in between the pads and twisted it to retract the pistons. Some people use pliers for this, but I didn't want to mar the pads or the shiny caliper paint.



9. Cut the zip-tie and slide the caliper over the rotor. Reinstall the caliper bolts and torque to 70 foot-pounds.

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10. Shoot the whole thing with Brake Cleaner to remove any contamination on the rotor (grease, beer etc.) Beautiful.



11. Do other side.

12. Reinstall front wheels, lower car, torque wheel nuts in criss-cross pattern to 94 foot-pounds. (130 NM)

13. Test drive carefully: listen for any grinding, apply brakes gently at first, feel for pulling side to side or any unusual feedback from the steering wheel or brake pedal.

14. That's it, you're done! Total time for this project-- about 45 minutes for the first rotor, and then 20 minutes for the second.

A well-maintained car is a happy car.

[Planter91C2]

nice job john, if everyone knew how easy disc brake service was it would put the brake shops out of business

i notice in the second pic you posted, the "before picture" there is a rub mark in the fenderwell. i presume this is from the front tire. i have this also and am worried. do you know if this is normal?

thanks.

[304065]

Daryl,

If you were running the stock "Design 90" wheels I would think any rubbing would be abnormal. I have a set of 17s that have a 993 part number and they are probably larger than stock, hence the rubbing. I remember Adrian Streather saying that the 964 was equipped at the factory with steering limiters to prevent rubbing- maybe they can be adjusted?

Thanks for the feedback!

JFC

[scotsman60]

John,


I did this same job a month or so ago and found it to be very easy BUT I believe that it's recomended to fit newpads when you fit new rotors.

This makes sense to me because you want the pads to be matched to the rotors and if the old pads are worn unevenly radially then there could be a problem in terms of more rapid rotor and pad wear during bedding in.

I fitted new pads when I replaced the rotors but then again my pads were shot anyway....


Doug

[Mike Feinstein]

C'mon John, the fronts are a breeze....did mine a few months ago. How about the same coverage when you do your rears? Soon as you discover you need a 10mm allen that's about 6" long and need a long breaker bar to bust 'em loose, the fun goes out of it....especially if you don't have a lift. You can only access the upper caliper bolt by fitting the allen through a hole in the control arm. Once you accomplish this you have NO leverage. Even if you can fit a breaker bar in the space available (with the car a foot off the ground) there's no room to swing it .

Fun, fun, fun