Chevrolet Full Size Cars 1979-1989

Evaporative Emissions Control System.

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Fig. Fig. 1 Cut-away view of a common evaporative emission canister



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Fig. Fig. 2 The vapor canister is often mounted in the front left portion of the engine compartment on these vehicles

This system, standard on all gasoline vehicles, eliminates the release of unburned fuel vapors into the atmosphere. The system should be checked for damage (and the filter replaced, if applicable) every two years or 30,000 miles. The only periodic maintenance required on all systems is an occasional check of the connecting lines for kinks or other damage and deterioration. Lines should only be replaced with quality fuel line or special hose marked evap .

A few of the early model vehicles covered by this guide are equipped with a replaceable canister filter. This filter is located in the bottom of the carbon canister located in the engine compartment and should be removed and replaced at each service interval.

Later model vehicles are equipped with a sealed canister assembly. Because of the sealed assembly, no other service is required or possible. If damaged, the entire canister assembly must be replaced. For further details on the evaporative emission control system please refer to of this guide.

FILTER REPLACEMENT



A few of the early model vehicles covered by this guide are equipped with an open canister. On the bottom of these canisters there is a replaceable filter. All later model vehicles are equipped with a closed or sealed canister on which no service is possible.

  1. Tag and disconnect all vapor hoses which are connected to the charcoal canister.
  2.  
  3. Loosen the retaining clamps or mounting bracket and then lift the canister from the vehicle.
  4.  
  5. Grasp the filter in the bottom of the canister with your fingers, then squeeze and pull it out from under the lip surface or from under the retainer bar.
  6.  

To install:

  1. Install a new filter to the bottom of the canister by squeezing and carefully inserting the filter into the canister. Make sure the edges are tucked under the canister lip.
  2.  
  3. Position the canister assembly in the vehicle and secure using the retainers.
  4.  
  5. Connect all vapor hoses to the canister as noted during removal.
  6.  

 
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