Fuel Tank: Description and Operation
Fuel Tank Insulators And Mountings:
FUEL TANK
The fuel tank is located under the rear of the vehicle and is the fuel reservoir. The fuel pump and fuel level sending unit assembly are mounted in the fuel tank as one assembly. The fuel tank assembly also consists of the fuel filler neck and filler cap.
Fuel And Vapor Pipes:
FUEL FILLER NECK
To help prevent refueling with leaded fuel, the fuel filler neck has a built-in restrictor and deflector. The opening of the restrictor will accept only the smaller unleaded gasoline nozzle which must be fully inserted to bypass the deflector. Attempted refueling with a leaded fuel nozzle will result in fuel splashing back out of the filler neck.
Fuel Filler Cap:
FUEL TANK FILLER CAP
The fuel tank filler neck is equipped with a screw type cap. The threaded part of the cap requires several turns counterclockwise to remove. The long threaded area was designed to allow any remaining fuel tank pressure to escape during the cap removal operation. A ratchet type torque limiting device prevents over-tightening. To install, turn the cap clockwise until a clicking noise is heard. This signals that the correct torque has been reached and the cap is fully seated.
NOTE: If a fuel filler cap requires replacement, only a cap with the same features should be used. Failure to use the correct cap can result in a serious malfunction of the system.
FUEL FEED AND RETURN PIPES/HOSES
The fuel feed and return pipes and hoses carry fuel from the fuel sender assembly to the fuel rail assembly. The fuel feed and return pipes and hoses consist of four sections:
The rear fuel pipe assemblies are located from the top of the fuel tank to the chassis fuel pipes. The rear fuel pipes are constructed of nylon.
The chassis fuel pipes are located under the vehicle and connect the rear fuel pipes to the engine compartment connecting fuel pipes. These pipes are constructed of steel.
The engine compartment connecting fuel pipes connect the chassis pipes to the engine fuel pipes. These fuel pipes are routed from the chassis fuel pipes under the vehicle and behind the front driver side wheel house liner to the engine compartment. These fuel pipes are constructed of nylon.
NYLON FUEL VAPOR PIPES
Nylon fuel pipes are designed to perform the same job as the steel or flexible fuel lines they replace. Nylon pipes are constructed to withstand maximum fuel system pressure, exposure to fuel additives, and changes in temperature. There are two sizes used: 3/8" ID for the fuel feed, and 5/16" ID for the fuel return.
The fuel feed and return pipes are assembled as a harness. Retaining clips hold the pipes together and provide a means for attaching the pipes to the vehicle. Sections of the pipes that are exposed to chafing, high temperature or vibration are protected with heat resistant rubber hose and/or corrugated plastic conduit.
Nylon fuel pipes are somewhat flexible and can be formed around gradual turns under the vehicle. However, if forced into sharp bends, nylon pipes will kink and restrict fuel flow. Also, once exposed to fuel, nylon pipes may become stiffer and are more likely to kink if bent too far. Special care should be taken when working on a vehicle with nylon fuel pipes:
CAUTION: To Reduce the Risk of Fire and Personal Injury:
- Always cover nylon fuel lines with a wet towel before using a torch near them. Also, never expose the vehicle to temperatures higher then 1150C (239°F) for more than one hour, or more than 90°C (194°F) for any extended period.
FUEL LINE "O" RINGS
The fuel line "O" rings used are made of Viton. They are brown in color. Viton is less affected than rubber by the additives used in many fuels. Therefore, rubber should not be used.