Test Procedure

NOTE: Most vacuum gauges have a normal band indicated on the gauge face.


1. Bring the engine to normal operating temperature.
2. Connect Vacuum/Pressure Tester 164-R0253 or equivalent to the intake manifold (9424).
3. Run the engine at the specified idle speed.

NOTE: The vacuum gauge should read between 51-74 kPa (15-22 in-Hg) depending upon the engine condition and the altitude at which the test is performed. Subtract 3.37 kPa (1 in-Hg) from the specified reading for every 304.8 m (1,000 feet) of elevation above sea level.

4. The reading should be steady. If necessary, adjust the gauge damper control (where used) if the needle is fluttering rapidly. Adjust damper until needle moves easily without excessive flutter.

INTERPRETING VACUUM GAUGE READINGS
A careful study of the vacuum gauge reading while the engine is idling will help pinpoint trouble areas. Always conduct other appropriate tests before arriving at a final diagnostic decision. Vacuum gauge readings, although helpful, must be interpreted carefully.