Vacuum Brake Booster Diaphragm Position Sensor: Service and Repair

Removing and installing distance sensor





Information





Overview: Distance sensor

The distance sensor -1- is located on the left in the engine compartment and is fitted above the brake master cylinder on the brake booster -2-.

Preliminary work

1. Remove wiper arms at the left and right.
2. Remove cowl panel cover.
3. Remove trim panel in the engine compartment.
4. Remove the brake master cylinder.

Removing distance sensor

Danger:
Porsche Stability Management does not work without values for the current brake pressure.
^ Danger of personal injury and material damage when the hydraulic unit is not calibrated.

-> After assembly of the brake master cylinder or hydraulic unit, the pressure sensor must be calibrated with the Porsche System Tester.

-> To do this, calibrate the pressure sensor in the menu >>PSM>> Calibration [[Pressure sensor]].

-> The security code is stored under menu >>PSM>> Actual values [[]]Security code]]. The code is entered in the last four positions.

Information:
^ Before disconnecting the connector from the brake master cylinder (pressure sensor) first wipe off any moisture with a lint-free cloth.

^ Brake lines are to be sealed with suitable plugs.

^ In order to catch escaping brake fluid, place a cloth under the brake booster.

Information:
^ In the case of assembly work on the hydraulic connections, the electrical plug connections on the brake master cylinder must always be connected. This prevents the plug connections on the brake master cylinder and the inside of the plugs being splashed with brake fluid or water.

^ Clean any plug connections that have become dirty or damp during removal or fitting with a lint-free cloth.

^ Brake fluid on electrical contacts (even thinned brake fluid) leads to corrosion and may cause faults in the system.

^ Remove any escaping brake fluid immediately; if necessary, rinse with water and dry.





Removing distance sensor

1. Remove the distance sensor.
1.1. Pull off electric cable plug on the distance sensor -1-.
1.2. Insert a small screwdriver into the groove -see arrow- for the circlip -2-. Then press the circlip -2- up and lever it off.
1.3. Pull out the distance sensor -1- from the brake booster.

Installing distance sensor

Danger:
Porsche Stability Management does not work without values for the current brake pressure.
^ Danger of personal injury and material damage when the hydraulic unit is not calibrated.

-> After assembly of the brake master cylinder or hydraulic unit, the pressure sensor must be calibrated with the Porsche System Tester.

-> To do this, calibrate the pressure sensor in the menu >>PSM >>Calibration>>[[Pressure sensor]].

-> The security code is stored under menu >>PSM >>Actual values [[Security code]]. The code is entered in the last four positions.





Installing distance sensor

1. Install the distance sensor.
1.1. Insert the distance sensor -1- as far as it will go on the brake booster -3-.
1.2. Fit a new circlip -2- and check that the circlip is seated flush in the groove all the way around.
1.3. Connect electric cable plug to the distance sensor -1-.

Subsequent work

1. Install the brake master cylinder.
2. Install trim panels in the engine compartment.
3. Install wiper arms at the left and right.
4. Bleed the hydraulic system.

Do not top up the brake fluid level above the -MAX- marking after bleeding the system.





Brake fluid reservoir

5. Read out the fault memory and erase it if necessary.

PIWIS Tester 9718