GM Full Size Vans 1987-1997 Repair Guide

Evaporative Canister



See Figure 1

Click image to see an enlarged view

Fig. Fig. 1: The EVAP canister on 1996-97 models (arrow) is secured to the frame rail, beneath the van

The only regular maintenance that need be performed on the evaporative emission canister is to regularly change the filter (on those 1987-90 models which utilize one; 1991-97 vans do not have a canister filter) and check the condition of the hoses. If any hoses need replacement, use only hoses which are marked EVAP. No other type should be used. Whenever the vapor vent hose is replaced, the restrictor adjacent to the canister should also be replaced.

The evaporative emission canister is either located on the left side of the engine compartment or is secured to the underbody of the vehicle, with a filter located in its bottom (if applicable).

For further information on the evaporative emission system, please refer toChapter 4of this guide.

To service the canister filter:
  1. Note the installed positions of the hoses, tagging them as necessary, in case any have to be removed.
  3. Loosen the clamps and remove the canister.
  5. Pull the filter out and throw it away.
  7. Install a new canister filter.
  9. Install the canister and tighten the clamps.
  11. Check the hoses.