Cruise Control Vacuum Reservoir: Description and Operation

The vacuum reservoir is located under the left front headlamp, in front of the battery. It is made of plastic and does not contain any other parts, such as a check valve.

The reservoir stores engine vacuum. Manifold vacuum is supplied from the brake booster check valve. The speed control vacuum supply hose has a check valve at the source (brake booster) to maintain the highest available vacuum level in the servo, reservoir and vacuum hoses. When engine vacuum drops, as in climbing a grade while driving, the reservoir supplies the vacuum needed to maintain proper speed control operation. The vacuum reservoir cannot be repaired and must be replaced if faulty.