Test sequence

Disconnect vacuum hose of the combination valve to be checked at Y-piece (arrow).

Fig 1: Disconnecting Vacuum Hose Of Combination Valve
Connect VAG1390 hand vacuum pump to vacuum hose of the valve to be checked.

Fig 2: Connecting VAG1390 Hand Vacuum Pump To Vacuum Hose Of Valve

NOTE: Do not use pressurized air for the following test!

Remove front noise insulation.
Disconnect pressure hose (arrow) between Secondary Air Injection (AIR) Pump Motor and connecting line and blow into it with light pressure.

Fig 3: Disconnecting Pressure Hose

Both combination valves must be closed.

NOTE: To disengage, compress the buttons at the hose coupling.

Operate hand vacuum pump.
The respective combination valve must open.

If the combination valve does not open or it is constantly open:

Replace the respective combination valve. See COMBINATION VALVES, REMOVING AND INSTALLING .