Swift L4-1298cc 1.3L SOHC MFI (1997)
Fuel Filler Cap: Description and Operation
The fuel tank filler neck has a vacuum cap. A ratchet tightening device on the threaded fuel filler cap reduces the chances of incorrect installation, which
would prevent sealing fuel vapors. After the gasket on fuel filler cap and the filler neck flange contact, the ratchet produces a loud clicking noise,
indicating the seal has been set. This cap has a vacuum relief valve inside. The vacuum relief valve opens to relieve the vacuum created in the fuel tank.