WM 300101 Checking Clutch Booster Circuit - As Of Model Year 2010 (Turbo Coupe, Turbo S Coupe, Turbo CABRIO, Turbo S CABRIO): Information: Notes

WARNING: This page does not describe the selected car, but rather 9 other vehicles, including the 2013 Porsche 911, 2012 Porsche 911, 2011 Porsche 911, 2010 Porsche 911, and 2009 Porsche 911. However, it is still accessible from the selected car via links, so may be relevant.

Clutch actuation, for the 911 Turbo, is assisted by a hydraulic auxiliary force (clutch booster circuit). This hydraulic auxiliary force acts on the clutch slave cylinder when de-clutching. A tandem pump -1- is used instead of the hydraulic single pump for power steering (997 naturally aspirated engine) in order to generate the auxiliary force.

Tandem pump (assembly 2 to 5)
Pressure control valve for the clutch booster circuit (with integrated pressure retaining valve)
Hydraulic pump for clutch booster circuit
Hydraulic pump for steering
Shared supply tank/reservoir (Pentosin reservoir) for the clutch booster circuit and power steering

Fig 1: Identifying Hydraulic Pump Components (Model Year 2010)

Courtesy of PORSCHE CARS NORTH AMERICA, INC.

A pressure accumulator -arrow- is screwed into the clutch slave cylinder. If the engine is switched off (with the system intact), the pressure accumulator -arrow- allows up to 20 clutch pedal actuations until an increase in pedal pressure is clearly felt. The booster circuit is then depressurized (pressure accumulator is empty).

Fig 2: Locating Pressure Accumulator

Courtesy of PORSCHE CARS NORTH AMERICA, INC.