Vacuum Brake Booster Check Valve: Testing and Inspection

VACUUM HOSE (CHECK VALVE)
INSPECTION
1. Disconnect the brake booster vacuum hose (check valve built in) (A) at the booster.
2. Start the engine and let it idle. There should be vacuum available. If no vacuum is available, the check valve is not working properly. Replace the brake booster vacuum hose and check valve and retest.