Procedure

PROCEDURE





1. Remove the brake booster vacuum supply line (3) together with the non-return valve (2) from the brake booster (1).





2. Check the brake booster vacuum supply line at the non-return valve upstream from the brake booster for contamination of oil. Insert a tightly rolled up corner of a non-reusable lint free white shop towel (see arrow) into the non-return valve (2). If the towel does not indicate any engine oil residue, proceed to step 4.

3. If the line exhibits contamination with engine oil, proceed to step 5.





4. Replace the following components only if oil contamination is NOT found. Refer to the applicable parts list for each model.

^ Vacuum supply line and clamp. Refer to Repair Instruction REP 11 66 000 Removing and installing vacuum pump (vacuum pipe and clamp installation).

5. Replace the following components only if oil contamination is found. Refer to the applicable parts list for each model.

^ Brake master cylinder and 0-ring. Refer to Repair Instruction REP 34 31 505 Removing and installing or replacing brake master cylinder.

^ Brake servo unit and seal. Refer to Repair Instruction REP 34 33 505 Removing and installing or replacing brake booster.

^ Vacuum supply line and clamp. Refer to Repair Instruction REP 11 66 000 Removing and installing vacuum pump (vacuum pipe and clamp installation).