Vacuum Diaphragm Test

Heated Inlet Air System:

Heated Inlet Air System Test:

1. Remove air cleaner from engine and allow engine to cool down to 115°F (46°.).

2. Using a suitable vacuum pump, apply 20 inches Hg vacuum to the sensor.

- If the door is in the up (heated air) position vacuum diaphragm is operating properly. Replace the sensor and repeat the SYSTEM TEST procedure

- If the door is not in the up (heated air) position, check the vacuum diaphragm (proceed to step 3).

3. To test the diaphragm, apply 20 inches of vacuum with a vacuum pump.

- The diaphragm should not bleed off more than 10 inches of vacuum in 5 minutes.

- The door should not lift off the bottom of the snorkel at less than 2 inches of vacuum.

- The door should be in full up (heated air) position with no more than 4 inches of vacuum.

4. If the diaphragm fails any of the above, replace diaphragm.

5. If the diaphragm performs properly but proper temperature is not maintained, replace the sensor and repeat the SYSTEM TEST procedure.