911 Turbo AWD F6-3600cc 3.6L SOHC Twin Turbo (1997)
Brake Bleeding: Service and Repair
With Hydraulic Brake Booster
Bleeding The Brakes
Caution: The following description is only applicable to vehicles fitted with a hydraulic brake booster.
Important notes
Use only new DOT 4 brake fluid. Observe correct brake fluid grade.
Due to the fact that the brake fluid change interval is set to 3 years in conjunction with the use of a special DOT 4 brake fluid, only this
type of brake fluid must be used when bleeding the brakes.
This Porsche brake fluid is available under the following part numbers:
Contents 1 liter = 000.043.202.09
Contents 30 liters = 000.043.202.66
The lower half of the brake fluid reservoir is subdivided into separate chambers.
Brake Fluid
The special Porsche brake fluid offers superior properties. Compared to conventional brake fluid grades (as used prior to MY '93), its particular
features are a further reduction of water absorption and a higher wet and dry boiling point.
Note on water absorption: A water content of as little as 2% in the brake fluid will be enough to reduce the boiling point by approx. 60°C.
As a rule, only the special Porsche brake fluid should be used (even for topping up). If the earlier type of brake fluid (as specified up to MY '93) is
mixed with the special Porsche brake fluid, this will lead to an unnecessary reduction of the safety margin.
Both brake fluids are of amber color.
Bleeding Procedure / Subdivision
1. Bleeding the brake master cylinder circuits
Includes: Partial bleeding (simplified bleeding) of brake booster circuit (provided that no booster circuit components have been dismantled).
If parts of the booster circuit have been dismantled, start by bleeding the booster circuit completely. See Re- 1.
2. Bleeding the ABD circuit (ABD = Automatic Brake Differential) in the hydraulic unit if the hydraulic has been replaced or removed. See Re-
2.
3. Bleeding the brake booster circuit if parts of the booster circuit or the system (including the suction side of the pump unit) have been
opened. See Re- 3.
Re- 1: Bleeding The Brake Master Cylinder Circuits
Includes: Partial bleeding (simplified bleeding) of the brake booster circuit.
Important notes
Depressurize booster circuit prior to bleeding.
Do not depressurize by actuating the brake pedal but rather at the bleeding valve of the pressure accumulator.
Caution: Start by filling the accumulator completely (with ignition key in position 1, actuate brake pedal until pump starts to run). After the
pump has switched off, pull off electrical connector and release pressure completely from accumulator vent valve. Open bleeder valve
slowly and keep bleeder hose in place.
