How to change pads and or rotors on a 996 GT2 or GT3
01-30-2006, 01:26 PM
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How to change pads and or rotors on a 996 GT2 or GT3
It isn't hard. With its racing heritage Porsche makes pads and rotors easy to change!
Important - it is best to break in new pads on a used rotor. It is best to break in new rotors with used pads. If you can avoid changing both at the same time, especially with racing pads.
To change pads, loosen wheel bolts. Jack up the car and remove the wheel. Turn the steering wheel to make it easier to reach the caliper and pads. Remove the bolt going through the top of the caliper. Use a socket wrench on the back (towards the center of the car) side of the caliper. It's a 13 mm.
Remove the bolt - this involves pressing down on the flat spring which lies on top of the caliper and presses down on the pads. Press hard - it is a firm spring. Remove Bolt. Then slide out (very carefully) the pad wear sensors, they are ceramic things which fit into slots at the top of each pad. Observe how the wires were routed so you can put them back correctly. They break easily so use a lot of finesse and little brute strength. If you break one, use an expression which rhymes with "bucket" and tie-wrap the useless wire to someplace convenient. You will no longer have a pad warning sensor but GT3 owners replace the pads long long before they are worn down to nothing. Some race pads do not have provisions for the sensors at all. If this is the case tie-wrap them out of the way.
Remove the flat spring. Lift out the pads. Use a worn pad to push (lever) in the caliper pistons. They need to be flush so you can drop in the new pads. Be careful, there are anti vibration dampers to prevent or minimize brake squeal which are round spider-web ish spring things (sorry for using technical terms) that fit into the caliper pistons. If they fall out, re-insert. This can be a bit of a pain, be patient, they are held in by friction and, if they aren't pushed in flush you'll hit them with the edge of the new pad and make them fall out. Re-insert, lever the pistons flush (more flush this time) and carry on.
Drop in new pads. They should drop in. Do not use force. I repeat do NOT hammer them in. If they are too tight make sure the pistons are pushed flush with the inside edge of the caliper. If you have new rotors and new Pagid RS-19 pads they may not fit. This being the case, use a belt sander to remove 1 mm of pad material. Wear a mask while doing this. Lots of ventilation is a good idea too. Alternately, call Larry Herman- he is an expert at grinding down pads. If you are using OEM pads, this will not be an issue. If you are using the Pagids and the rotors are fairly worn this will not be an issue either. Alternately, install the pads without the anti vibration dampers - this will do no harm but the brakes will squeal more. Re-install once the pads and rotors have worn down enough to reduce the noise.
Then, reinsert the pad sensors, they can only go in one way. Put back the flat spring. Insert bolt - press down on the flat spring to allow the bolt to get all the way through. Make sure the bolt head is lined up correctly, two sides of it are flat and the recess in the caliper is not round - it has two flat sides to match the bolt head. Attach and tighten the nut on the back side. A good hard tug on a 3/8 inch socket wrench will do the job. Put back the wheel and once lowered, retorque to 94 foot lbs. Get in the car, switch on the ignition and pump the brake pedal. It may go to the floor at first. Don't panic. This is normal. Pump the pedal until it's firm and you are done.
Rotor Replacement - jack up and remove wheel as above. Turn the wheel to get access to the back of the caliper. Remove the 10 mm allen head bolts. You will need a socket wrench with a 10 mm allen head driver to do this. remove the caliper - you should be able to do this without removing the pads. You may have to encourage it by tapping it upwards. I use a piece of 1 x 3 pine and tap the wood with hammer. Note, I said tap, it doesn't take much.
The rotor is held in place by a couple of philips head screws. remove them and pull off the rotor. Before installing a new rotor check to make sure you have the right one. They come in pairs and there is a left (driver side) and a right (passenger) side. Look for a "L or R" printed on the rotor and plcae accordingly. Put on the new rotor, re-insert the screws. Note the screws are just there to allow easy replacement, the real work is done by the wheel bolts. Replace the caliper and bolt it in with the 10 mm allen head bolts. Torque to 68 foot pounds, a very hard pull on a 10 inch long socket wrench has worked for me. It's about the same effort as it takes to loosen them in the first place. In truth you should replace the bolts - they are one time only units according to Porsche.
Put back wheel, lower car, torque as above and also pump the brakes.
With a good floor jack, if you jack the car with one of the front lift points you will lift both sides of the car. The GT3 chassis is very stiff. Use a jack stand on the side opposite the jack to be safe - just in case the jack decides to let go.
Pads take about an hour to change both sides. The rotors a little less.
Rear pads are similar to the above except there is no bolt. That makes the job easier. Instead there is a metal rod secured by a cotter pin in place of the bolt and spring. Other than that it is the same as the front.
Break in the pads and/or rotors following the manufacturers suggestions for the pads. If you don't know, go to www. stoptech.com and read all about it.
Important - it is best to break in new pads on a used rotor. It is best to break in new rotors with used pads. If you can avoid changing both at the same time, especially with racing pads.
To change pads, loosen wheel bolts. Jack up the car and remove the wheel. Turn the steering wheel to make it easier to reach the caliper and pads. Remove the bolt going through the top of the caliper. Use a socket wrench on the back (towards the center of the car) side of the caliper. It's a 13 mm.
Remove the bolt - this involves pressing down on the flat spring which lies on top of the caliper and presses down on the pads. Press hard - it is a firm spring. Remove Bolt. Then slide out (very carefully) the pad wear sensors, they are ceramic things which fit into slots at the top of each pad. Observe how the wires were routed so you can put them back correctly. They break easily so use a lot of finesse and little brute strength. If you break one, use an expression which rhymes with "bucket" and tie-wrap the useless wire to someplace convenient. You will no longer have a pad warning sensor but GT3 owners replace the pads long long before they are worn down to nothing. Some race pads do not have provisions for the sensors at all. If this is the case tie-wrap them out of the way.
Remove the flat spring. Lift out the pads. Use a worn pad to push (lever) in the caliper pistons. They need to be flush so you can drop in the new pads. Be careful, there are anti vibration dampers to prevent or minimize brake squeal which are round spider-web ish spring things (sorry for using technical terms) that fit into the caliper pistons. If they fall out, re-insert. This can be a bit of a pain, be patient, they are held in by friction and, if they aren't pushed in flush you'll hit them with the edge of the new pad and make them fall out. Re-insert, lever the pistons flush (more flush this time) and carry on.
Drop in new pads. They should drop in. Do not use force. I repeat do NOT hammer them in. If they are too tight make sure the pistons are pushed flush with the inside edge of the caliper. If you have new rotors and new Pagid RS-19 pads they may not fit. This being the case, use a belt sander to remove 1 mm of pad material. Wear a mask while doing this. Lots of ventilation is a good idea too. Alternately, call Larry Herman- he is an expert at grinding down pads. If you are using OEM pads, this will not be an issue. If you are using the Pagids and the rotors are fairly worn this will not be an issue either. Alternately, install the pads without the anti vibration dampers - this will do no harm but the brakes will squeal more. Re-install once the pads and rotors have worn down enough to reduce the noise.
Then, reinsert the pad sensors, they can only go in one way. Put back the flat spring. Insert bolt - press down on the flat spring to allow the bolt to get all the way through. Make sure the bolt head is lined up correctly, two sides of it are flat and the recess in the caliper is not round - it has two flat sides to match the bolt head. Attach and tighten the nut on the back side. A good hard tug on a 3/8 inch socket wrench will do the job. Put back the wheel and once lowered, retorque to 94 foot lbs. Get in the car, switch on the ignition and pump the brake pedal. It may go to the floor at first. Don't panic. This is normal. Pump the pedal until it's firm and you are done.
Rotor Replacement - jack up and remove wheel as above. Turn the wheel to get access to the back of the caliper. Remove the 10 mm allen head bolts. You will need a socket wrench with a 10 mm allen head driver to do this. remove the caliper - you should be able to do this without removing the pads. You may have to encourage it by tapping it upwards. I use a piece of 1 x 3 pine and tap the wood with hammer. Note, I said tap, it doesn't take much.
The rotor is held in place by a couple of philips head screws. remove them and pull off the rotor. Before installing a new rotor check to make sure you have the right one. They come in pairs and there is a left (driver side) and a right (passenger) side. Look for a "L or R" printed on the rotor and plcae accordingly. Put on the new rotor, re-insert the screws. Note the screws are just there to allow easy replacement, the real work is done by the wheel bolts. Replace the caliper and bolt it in with the 10 mm allen head bolts. Torque to 68 foot pounds, a very hard pull on a 10 inch long socket wrench has worked for me. It's about the same effort as it takes to loosen them in the first place. In truth you should replace the bolts - they are one time only units according to Porsche.
Put back wheel, lower car, torque as above and also pump the brakes.
With a good floor jack, if you jack the car with one of the front lift points you will lift both sides of the car. The GT3 chassis is very stiff. Use a jack stand on the side opposite the jack to be safe - just in case the jack decides to let go.
Pads take about an hour to change both sides. The rotors a little less.
Rear pads are similar to the above except there is no bolt. That makes the job easier. Instead there is a metal rod secured by a cotter pin in place of the bolt and spring. Other than that it is the same as the front.
Break in the pads and/or rotors following the manufacturers suggestions for the pads. If you don't know, go to www. stoptech.com and read all about it.
