Ford Corsar Repair Manual page 390

EVAPORATIVE EMISSION CONTROL SYSTEM
4
To fuel tank
S E C 9 6
5. If air flow through the drain tube is poor, clean the bottom filter
by blocking off the fuel tank tube connector and blowing com-
pressed air at approximately 300 kPa through the purge port.
Recheck air flow through the filter as in Step 4. If air flow
through the drain tube is still poor, replace the canister.
6. Apply low pressure compressed air (20-35 kPa) to one of the
canister ports while the others are blocked off if any air leaks
from the top section of the canister, i.e. around the tubes or
lid, the canister must be replaced.
Fuel Tank Vacuum Relief Valve Inspection
1. Wipe clean valve housing.
2. Apply vacuum. A slight resistance indicates that valve is in
good mechanical condition.
3. If valve is clogged, or if no resistance is felt, replace cap as an
assembled unit.
FUEL CHECK VALVE
1. Blow air through connector on fuel tank side.
A considerable resistance should be felt and a portion of air
flow should be directed toward the canister.
2. Blow air through connector on canister side.
Air flow should be smoothly directed toward fuel tank.
3. If fuel check valve is suspected of not properly functioning
in steps 1 and 2 above, replace it.