Fuel Tank: Notes

Fig 1: Identifying Fuel Tank Valve

Courtesy of GENERAL MOTORS CORP.

The fuel tank is blow-molded of high-density polyethylene. This material is multi-layer in construction to enhance its ability to minimize leakage of fuel vapors to the atmosphere (impermeability). It is generally 4.0 mm to 5.0 mm (101.6 in. to 127 in.) in thickness and incorporates two valves which operate during the refueling process.

Both these valves are not serviceable, both are molded into fuel tank shell, Fill Limit Vent Valve (FLVV), and grade vent valve.