Vacuum Control System Diagnosis

This control is used with the heater and A/C (manual) systems.

Use an adjustable Vacuum Test Gauge (C-3707) and a suitable vacuum pump to test heater-A/C control vacuum. With a finger placed over the end of test hose, calibrate vacuum control valve on the test gauge to obtain -27 kPa (8 in. Hg.). Release and block the end of the test hose several times to verify vacuum setting.