Evaporative Emissions System: Service and Repair

CAUTION: Ensure all vacuum hoses and electrical wires are routed clear of the exhaust manifold to prevent deterioration due to the high temperature. Vacuum hoses should always be a minimum of three inches from the exhaust manifold. When servicing the charcoal canister, mark then disconnect vacuum hoses from charcoal canister to ensure proper installation.


The only service normally required for the system is to replace the filter in the bottom of the canister every 12,000 miles on 1970-76 vehicles, every 18,000 miles on 1977-82 Heavy Duty Cycle vehicles, or every 30,000 miles on 1977-82 Light Duty Cycle vehicles. More frequent filter replacement may be needed if the vehicle is often operated in dusty areas.

When replacing hoses in this system, use only special fuel resistant hose intended for such use.