Vacuum Brake Booster: Testing and Inspection
Brake servo, leak testSpecial tool: 999 5843
Z1. Disconnect brake servo hose (1) from intake manifold
Z2. Connect vacuum pump with tee-piece and hose as illustrated
1. Existing hose
2. Tee-piece, P/N 12 76 216-7
3. Vacuum pump 999 5843
4. Hose, 100 mm, P/N 12 72 328-4
5. Clips (two), P/N 943 471-3
6. Plug
Pump up vacuum and read gauge.
Z3. If reading falls, leakage is probably present in:
^ non-return valve/seal. Replace seal.
^ diaphragm. Replace complete servo unit.
Z4. Remove vacuum pump. Reconnect servo hose to intake manifold.