Check the evaporation control system every 15,000 miles (24,000 km). Check the fuel and vapor lines and the vacuum hoses for proper connections and correct routing, as well as condition. Replace clogged, damaged or deteriorated parts as necessary.
If the charcoal canister is clogged, it may be cleaned using low pressure (no more than 43 psi) compressed air. The entire canister should be replaced every 5 years/50,000 miles (80,450 km) or 60,000 miles (96,540 km) for 1978-82.
- Label the vacuum lines leading to the canister.
- Remove the vacuum lines attached to the canister.
- Unfasten the retaining bolts from the canister.
- Lift the canister up and remove the lower hose attached to the unit.
- Inspect the case for any cracking or damage.
- Using low pressure compressed air, blow into the tank pipe (flanged end) and check that air flows freely from the other ports.
- Blow into the purge pipe (next to tank pipe) and check that air does not flow from the other ports. If air does flow, the check valve has failed and the canister must be replaced.
- Never attempt to flush the canister with fluid or solvent. Low pressure air 43 psi (294 kPa) maximum may be used to evaporate any vapors within the canister. When applying the air, hold a finger over the purge pipe to force all the air out the bottom port.
- No carbon should come out of the filter at any time. Loose charcoal is a sign of internal failure in the canister.