Figure 1: Jack Stand Under Torsion Bar Cover
Figure 2: Removing "hairpins"
Figure 3: Tapping out Retaining Pins
Figure 4: Removal of Cross Spring
Figure 5: Removing Brake Pads
Figure 6: Oil Filter Removed
Figure 7: Pushing Back Pistons
Figure 8: Brake Rotor Revealed
Figure 9: Rust on Piston
Figure 10: Inspecting Brake Hoses
Figure 11: Lubro-Moly Hi-Tack Lube Spray
Figure 12: Reconnecting Sensor Wires
Figure 13: Brake Cross Spring
| The car used to demonstrate this procedure is
Bob Tindels 1983 911SC, but the procedure is similar for other Porsches.
Before starting, if your brake master cylinder is very full, draw off some of the fluid.
When you push back the caliper pistons, if the master cylinder is completely full, it can
overflow. BRAKE FLUID DESTROYS PAINT.
1. Jack up one side of the car. Put a jack stand under the rear
torsion bar end cover. (Figure 1)
2. Remove the wheel.
3. There are two pins holding the pads in each caliper. The front
pins have self-retainers, and can simply be tapped out from the outside, using a pin punch
or a nail. The retaining pins in the rear calipers have little hairpins (Figure 2) in the inboard end of each pin, which must be removed before
the pin can be tapped out. (Figure 3) After you remove one of the
retaining pins, you can take out the brake cross-spring. Note how it fits before removal,
so you can get it back in right. (Figure 4)
4. Remove the old pads. (Figure 5) If they are
stubborn, you may have to push back the piston first. (Figure 6)
Disconnect the brake pad sensor wire, if so equipped.
5. Push the both pistons all the way back into the caliper. To do
this, you can use a piece of hard wood, or a pair of channel-lock pliers. Just be careful
not to damage or ding anything. (Figure 7)
6. Inspect the rotors. If they have severe ridges, or if they are
worn below the minimum thickness, they will need to be resurfaced or replaced. The same is
true if they are warped or have excessive runout (a symptom of warpage or runout is
steering wheel shimmy when you apply the brakes). (Figure 8)
7. Inspect the calipers. If they are leaking fluid, or if the rubber
dust boot is damaged, they will need to be rebuilt or replaced. Rust on the exposed part
of the piston, next to the brake pad, is normal. (Figure 9)
8. Inspect the brake hoses for cracking or leakage. (Figure 10)
9. This is also a good time to inspect the shock absorbers. Any
evidence of fluid leakage indicates need for replacement. (Figure 8)
10. If the inspection of the rotors, calipers, and brake hoses is
satisfactory, proceed with the installation of the new pads.
11. Do not use the anti-squeal compound pad from your Friendly Local
Auto Parts Store on the back of the brake pads. This stuff turns to glue, and when you
need to replace the brake pads again, it will destroy the caliper dust boot when you pull
the pads out (dont ask how I know this). Many new brake pads come with an
anti-squeal coating already applied. It looks like a thicker coat of paint on the back of
the pads. If you want to use something more I recommend a LIGHT coat of Lubro-Moly Hi-Tack
Lube Spray. Be careful not to get this stuff on the braking surface of the pads, or on the
rotors. (Figure 11)
12. Insert the new pads the same way the old ones came out. Reconnect
the sensor wires, if so equipped. (Figure 12)
13. Insert one of the retaining pins, taking care that the hole for
the hairpin in the retaining pins of the rear calipers is accessible. Tap each
pin until it is fully seated. You should be able to see the end of the pin in its hole on
the outside of the caliper.
14. Insert the hairpin into the brake pad retaining pin.
15. Insert the brake cross spring (Figure 13),
and then the second retaining pin. Make sure that both ends of the brake cross spring
engage the retaining pins. The cross spring helps retract the pads, so they dont
drag on the rotors when you let off the brakes.
16. Repeat steps 2-15 for the other three calipers.
17. Reinstall the wheels. The correct torque for factory alloy wheels
and alloy lug nuts is 95 ft/lbs.
18. Top off the master cylinder. Use only fresh fluid from a sealed
container. We recommend a top-quality fluid such as Ate.
19. Pump the brake pedal a few times to return it to normal position.
20. Recheck the master cylinder brake fluid level.
CAUTION: New brake pads require a break-in period. Until they are
broken in, braking efficiency is reduced. Apply the brakes gently during break-in to
increase the life of pads and rotors.
It is not necessary to bleed the brakes after this procedure.
However, it is a good idea to completely flush and bleed the brake system at least every
Call our Parts Department at 1-888-280-7799 and we will fix you up with the best brake
pads for your usestreet or track (and some fresh brake fluid if you need it).