Resume Valve Test - Mechanical Cruise Control

1. Disconnect electrical connector to transducer hold terminal.
2. Apply suitable 12 volt source to the hold terminal connector cavity. Solenoid should engage.
3. Remove voltage source. Solenoid should disengage. A click should be heard each time the solenoid engages or disengages. Do not reverse polarity when applying power to the terminals as this may damage the radio noise suppression diode in the solenoid.

SERVO TEST
1. Remove vacuum hose from servo unit.
2. Apply approximately 14 inches of vacuum for 1 minute. Maximum vacuum leakage should not exceed 5 inches. If leakage limit is exceeded, replace servo unit. Cruise release vacuum brake valve and connecting hoses can be checked using this same method.

VACUUM REGULATOR TEST
Vacuum regulators are used on diesel engines only. Because of lower operating vacuum of diesel engines, cruise control system could become inoperative with just a very small vacuum leak.
1. Remove hose from transducer at regulator.
2. Attach vacuum gauge to regulator valve and start engine.
3. Vacuum should read between 6 and 7 inches Hg. If reading is below 6 or above 8, replace regulator valve.