Shadow L4-135 2.2L SOHC VIN D FI (1992)
Fuel Filler Cap: Description and Operation
Fuel Filler Cap Operation
Operation
Note:
The relief valves in the cap are a safety feature, and operate only to prevent excessive pressure or vacuum in the tank, caused by a malfunction
in the system or damage to the vent lines.
Prevents fuel system damage, by venting the system in the event of high internal pressure or vacuum.
Prevents fuel and vapors from escaping into the atmosphere, (except under extreme conditions).
^ If the pressure relief valve fails to open, the cap vents pressure to the atmosphere, (when pressure excedes the cap's limit).
^ Cap will allow air to enter the tank, if vacuum limit is exceded.