Evaporative Emissions System: Testing and Inspection

Evaporative Emissions Control System Schematic:

CANISTER CHECK

Apply a short length of hose to the bottom port of the canister and attempt to blow through it. There should be no restriction of air through the canister and out the top two ports. If there is a restriction, the canister is faulty and should be replaced. Apply the short length of hose to hose "B" and blow. Air should not pass through the canister and out hoses "A" or "C." If air passes through, the canister is faulty and should be replaced.

2-Way Check Valve:

TWO-WAY CHECK VALVE CHECK

^ Remove Two-way check valve.
^ Attempt to blow through it from fuel tank side (BLACK side of valve) to the canister side (orange side). Air should pass, but not easily. When blowing from orange side air should pass easily.
^ If the valve does not operate as indicated, replace two-way valve.

REMOVE:

a. Hoses from canister. Mark hoses to install on new canister.
b. Canister

INSTALL

a. Canister.
b. Hoses. Make sure connections are correct.