With Generic Scan Tool

Combination Valves, Checking

Recommended special tools and equipment

Special Tools and Equipment
- VAG1390 Hand Vacuum Pump

Test requirements:
- No leaks in vacuum lines or hose connections.
- Vacuum lines not clogged.







- Remove bolts (arrows) and remove engine covers -A- through -C-.







- Remove air distributor (arrows).

Leak test







- Pull hose from Secondary Air Injection (AIR) pump motor and blow in with light pressure (do not use pressurized air).
- Both combination valves must be closed, it must not be possible to blow through hose

If it is possible to blow through hose:
- Disconnect connecting line from Secondary Air Injection (AIR) pump motor to combination valve at one of the combination valves, close connecting line and blow through again.
- Replace the combination valve remaining on the connecting line

If it is no longer possible to blow through hose:
- Replace the combination valve that was removed from the connecting line

Function test







- Remove vacuum hose of the combination valve to be checked and connect the VAG1390 vacuum pump to the combination valve.







- Pull hose from Secondary Air Injection (AIR) pump motor and blow in with light pressure (do not use pressurized air).
- Operate hand vacuum pump.
The respective combination valve must open, it must be possible to blow through

If the respective combination valve does not open:
- Replace the combination valve

If the respective combination valve opens:
- Repeat function test at second combination valve.

NOTE:
- Use special tool 3231 and the Hazet carburetor adjustment key 4530.
- No special tools are necessary for the right combination valve.