Brake Caliper; Pccb Brake Disk Information - Porsche 2012 911 GT3 CUP Technical Manual

8.4.

Brake caliper

8.5.

PCCB brake disk information

The brake calipers fitted are of aluminium monobloc design. A 6-piston
caliper is used on the rear axle and a 4-piston caliper on the rear.
The caliper pistons are fitted with dust boots. When working on the brake
system, such as when changing brake pads, attention should be taken
that there is no dirt on the pistons when they are pressed into the caliper
body.
Porsche Motorsport provides a repair kit for brake calipers which includes
new pistons and seals.
There are two bleed nipples on each brake caliper. If a pressure
manometer is connected to the caliper it should be noted that the system
including manometer is bled.
The PCCB brake discs require careful handling, they are very sensitive to
mechanical influences such as, for example, knocks from the wheel when
fitting tyres or damage which can occur when cleaning the ventilation
holes with a drill bit.
Mechanically damaged brake disks must be replaced. The PCCB brake
disc wear can only be assessed by weight loss, and not, however, by the
reduction of the brake disc thickness. The wear indicators on the brake
disc are not relevant for use when racing. Precision weighing scales are
recommended to weight the brake discs. The weights should be
documented together with mileage. To guarantee precise documentation
of the brake discs the new weight of the brake discs and a sequential
number are engraved on the disc bell.
The brake disc weight loss must not exceed 100 g from the new weight.
If the weight loss exceeds 100 g the brake disc is worn out.
118