Changing rotors

[RJFabCab]

Can someone point me to a DIY for changing rotors on a MY2005 996 GT3?

My searches are coming up empty.

Thanks,

RJ

[Loren]

Pretty much the same for a GT3 -- be careful the rotors are directional.

http://www.renntech.org/forums/index.php?s...indpost&p=16992

[RJFabCab]

Pretty much the same for a GT3 -- be careful the rotors are directional.

http://www.renntech.org/forums/index.php?s...indpost&p=16992

Loren, as usual... you ROCK! :beer:

A couple of q's:

1. Is there a torque spec for the 2 philips screws holding the rotor? I know that the bulk of the support is done by the 5 wheel bolts.

2. I see that the torque spec for the caliper bolts is 63 ft/lbs. Can you verify that the torque spec for the bolt on the end of the retaining pin (the one that holds the caliper flat spring down) on the front calipers is 10 ft/lbs.? I recall mds using 10 ft/lbs.

3. I'm new to loctite. Should I use something like loctite 242 blue threadlocker on the philips screws, caliper bolts, or retaining pin bolt?

4. I haven't worked on a drum parking brake assembly. Can you elaborate? Is there a specific screw accessed through the threaded wheel bolt hole that allows adjustment of the parking brake? Does this screw have "notched" adjustments? Or, am I dealing with a screw to adjust cable slack regarding the parking brake lever?

I did find this: Parking brake adjustment

RJ

Edited April 10, 2006 by RJFabCab

[Loren]

1. No there is no spec in the manual. When the wheel is in place that screw is not going anywhere.

2. There is no torque spec specified in the manual - as I recall we guessed based on the size of the bolt - so 7.5 to 10 ft/lbs.

3. Porsche does not suggest any thread locking. It is likely too hot for it there anyway.

Porsche does recommend new caliper bolts. The GT3 bolts are 5 mm longer than a 996 and should be red (not silver).

4. http://www.renntech.org/forums/index.php?s...indpost&p=16992

Same type of an adjuster as on typical drum brakes. Rotate one direction and the brake pads are forced closer to the drums - rotate the other and they are pulled away from the drums.

[RJFabCab]

Loren, I took off the wheels and took a good look at the calipers/rotors. I have some more questions regarding changing the rotors.

1. The rotor caliper bolts appear to be allen head bolts. What size allen head wrench (metric) do these caliper bolts take?

2. Front rotors: after removing the 2 caliper bolts, will the caliper have enough room to swing off the rotor without removing anything else (such as brake lines)? It appears that the brake lines are rather fixed and that I would need to remove a 10 mm hex bolt (see green arrow) to be able to freely remove the caliper off of the rotor.

3. The bolt holding my retaining pin on the front calipers is 13 mm.

4. Rear rotors: After removing the 2 caliper bolts, should I be able to remove the caliper off the rotor without disconnecting anything else? Once again, it appears that I may need to remove a 10 mm hex bolt (see blue arrow) to be able to freely remove the caliper.

5. I'm still not clear on how to adjust the parking brake at the drum. I look through the threaded bolt hole and see 2 little brass looking pads/discs. How does this adjustment work at the rotor?

6. Regarding the parking brake, if the parking brake is released and the old left rear rotor turns freely, then there should not be a problem removing the old rotor and placing a new one, correct?

Edited April 11, 2006 by RJFabCab

[Loren]

1. On a standard 996 they are 10 mm hex. On a GT3 I think they are the same just longer.

2. Yes, you can remove the bracket. I usually just hang the caliper off the spring with a wire or twine so there is no pressure on the brake lines/fittings.

3. Ok, maybe you should write up a DIY for GT3 when you are done. ;)

4. If that is attached to the caliper wouldn't come off with the caliper?

5. You take regular screw driver and rotate the wheel - like you are prying it in the direction it will rotate. One direction tightens the parking brake shoes and the other way loosens them. Item 2 in the pic is the shoe adjustor. You are turning it to force the screw (lower part of 2) and the bushing (3) either to push the shoes out or bring them in.

6. Correct, if you can get the rotor off without loosening the brake shoes that is fine. Just realize you still may have to loosen the shoes a little to get the new rotor on.

[RJFabCab]

1. On a standard 996 they are 10 mm hex. On a GT3 I think they are the same just longer.

2. Yes, you can remove the bracket. I usually just hang the caliper off the spring with a wire or twine so there is no pressure on the brake lines/fittings.

3. Ok, maybe you should write up a DIY for GT3 when you are done. ;)

4. If that is attached to the caliper wouldn't come off with the caliper?

5. You take regular screw driver and rotate the wheel - like you are prying it in the direction it will rotate. One direction tightens the parking brake shoes and the other way loosens them. Item 2 in the pic is the shoe adjustor. You are turning it to force the screw (lower part of 2) and the bushing (3) either to push the shoes out or bring them in.

6. Correct, if you can get the rotor off without loosening the brake shoes that is fine. Just realize you still may have to loosen the shoes a little to get the new rotor on.

1. 10 mm hex. Got it.

2. Good advice on hanging the caliper to relieve tension.

3. I plan to if I actually see this project through! B)

4. Regarding the rear caliper, yes, the bracket will come off with the caliper, however, the bracket appears to house ABS (?) lines in addition to brake pad sensor lines and the ABS lines are fixed to the bracket with no slack. It looks like I'll have to remove the bracket to freely remove the rear caliper. They must be ABS lines... I can't think of anything else they would be.

5. I see. I was looking at the wrong part of the drum assembly. I was looking at part "7" rather than part "2" in your diagram.

6. Good. It shouldn't be a problem then once I learn how to adjust the rear drum brake.

Thanks for the help

Edited April 11, 2006 by RJFabCab

[0586slb]

I'd like to jump in here with a query: In what order do you adjust the drum mechanism and the handbrake cable mechanism? I'm thinking one will interact with the other. So adjusting the drum mechanism until the rotor is unable to turn and then back-off, will that give the required 5 clicks on the handbrake?

Chris

[Loren]

I'd like to jump in here with a query: In what order do you adjust the drum mechanism and the handbrake cable mechanism? I'm thinking one will interact with the other. So adjusting the drum mechanism until the rotor is unable to turn and then back-off, will that give the required 5 clicks on the handbrake?

Chris

According to the manual you do the handbrake handle first -- and last. If the handle can be pulled up more than 4 clicks (before apparent braking action) then it needs to be adjusted. Then adjust the brake shoes to the point where the rotor can not be spun - then back off 5 notches and make sure the rotor turns freely. Then go back to the handbrake handle and pull it up two clicks - adjust the turnbuckle (at the handbrake handle) so that the rotors just turn (with some difficulty). Release the handbrake and make sure the wheels turn freely.