Installation instructions for 74-89 Porsche 911 front 309mm to 331mm braking system
with Porsche OEM S4/993 C2 Caliper.
First I would like to thank you for choosing Pro Braking for you braking needs. We understand you have many great choices out in the 911 retail market, and we strive to do our best in keeping our kits out performing the others.
This instruction sheet is meant as a guild to the installation, and should not be substituted for any factory installation instructions.
Pre-assembly:
First step is to assemble the rotor hats to the rotors, the hat is round and has two circular hole patterns on it the inner pattern is 5 holes and the outer pattern is either 8 or 12. The hat is place on the front of the rotor, and 8- 5/16 bolts supplied are used to assemble; each bolt should have a stainless steal washer on it before inserting the bolt into the outer ring of holes. This will be a tight fit, place the rotors on a solid surface and use a wooden, or rubber mallet to get bolts flush on the face of the hat. Use the Jet-Nuts supplied to secure the hat to the rotor. The nuts will thread on a few turns by hand, but they will get tight right away, this is normal, the thread design allows the nut to lock on to the bolt making it unable to back off as a result of vibration and heat. Torque the hat to the rotor using the same specifications found in your maintenance manual for securing the rotor to the Hub of your 911. The picture bellow can be used as a reference. Complete this procedure for the second rotor and hat.
Vehicle Installation:
Please refer to a Porsche maintenance manual to remove your current brakes. Remove the stock caliper completely by removing the two bolts located in the rear of the caliper, and removing the brake line from the rear on the caliper. Once you have the Hub removed form the car, and you have unbolted the stock rotor from the rear of the hub you may install the new brake rotor in the same mounting holes as your stock rotor can from. Your new rotors are directional, and are each designed for a specific side of your car. To tell which rotor is your right, and which is your left you must look at the vanes in the rotor and how they bend. When the rotor is spinning in the forward direction the vane should blow air out around the outside of the rotor pulling cool air in from the center. The rotor below represents the left rotor spinning forward.
Installing the Caliper adapters:
The calipers adapted blocks are identical and not side specific. Install the block on the car with the two 40mm long allen bolts supplied (gold in color). The block mounts to car with the unthreaded holes in the block bolting the block to the 3.5” wide ears that your stock calipers where removed from (some trimming or heat shield removal might be needed depending on your year). When the block is tight on the car the allen bolt heads should be flush inside the block, and the thicker part of the block should be facing towards the front of the car. This will allow the radial mount caliper to be properly spaced off the center of the hub. Once the block is
on the car, continue to install the Hub/rotor on the car in accordance with the Porsche maintenance manual.
Last step is to bolt the caliper on to the caliper block. The Green 72mm bolts are used for this. Once the caliper is securely bolted on the block, use the supplied brake line pieces to plumb from the back of the caliper to the mounting point for the flex brake line on the bottom part of the strut.
Brake caliper Bleeding:
When bleeding the four piston caliper, bleed the outside section of the caliper first, then the inside. Always be careful on first moving the car to insure brakes are in proper working order. The front caliper may need to be bled again after about 5-20 miles of use to get all the air out of them. All questions on installation can be directed to service@probraking.com.
