Procedures
STANDARD PROCEDURE - DRAINING FUEL TANK
GAS POWERED
WARNING: The fuel system may be under constant fuel pressure even with the engine off. This pressure must be released before servicing fuel tank.
Two different procedures may be used to drain fuel tank: through the fuel fill fitting on tank, or using a diagnostic scan tool to activate the fuel pump relay. Due to a one-way check valve installed into the fuel fill opening fitting at the tank, the tank cannot be drained conventionally at the fill cap.
The quickest draining procedure involves removing the rubber fuel fill hose at the fuel tank.
As an alternative procedure, the electric fuel pump may be activated allowing tank to be drained at fuel rail connection. Refer to diagnostic scan tool for fuel pump activation procedures. Before disconnecting fuel line at fuel rail, release fuel pressure. Attach end of special test hose tool number 6631 or 6539 at fuel rail disconnection (tool number 6631 is used on 5/16 inch fuel lines while tool number 6539 is used on 3/8 inch fuel lines). Position opposite end of this hose tool to an approved gasoline draining station. Activate fuel pump and drain tank until empty.
If electric fuel pump is not operating, fuel must be drained through fuel fill fitting at tank. Refer to following procedures.
1. Release fuel system pressure.
2. Raise vehicle.
3. Thoroughly clean area around fuel fill fitting and rubber fuel fill hose at tank.
4. If vehicle is equipped with 4 doors and a 6 foot (short) box, remove left-rear tire/wheel.
5. Loosen clamp and disconnect rubber fuel fill hose at tank fitting. Using an approved gas holding tank, drain fuel tank through this fitting.
DIESEL POWERED
Two different procedures may be used to drain fuel tank: through the fuel fill fitting on tank, or using a diagnostic scan tool to activate the fuel pump relay. Due to a one-way check valve installed into the fuel fill opening fitting at the tank, the tank cannot be drained conventionally at the fill cap.
The quickest draining procedure involves removing the rubber fuel fill hose at the fuel tank.
As an alternative procedure, the electric fuel pump may be activated allowing tank to be drained at fuel rail connection. Refer to diagnostic scan tool for fuel pump activation procedures. Attach end of special test hose tool number 6631 or 6539 at fuel rail disconnection (tool number 6631 is used on 5/16 inch fuel lines while tool number 6539 is used on 3/8 inch fuel lines). Position opposite end of this hose tool to an approved diesel fuel draining station. Activate fuel pump and drain tank until empty.
If electric fuel pump is not operating, fuel must be drained through fuel fill fitting at tank. Refer to following procedures.
1. Release fuel system pressure.
2. Raise vehicle.
3. Thoroughly clean area around fuel fill fitting and rubber fuel fill hose at tank.
4. If vehicle is equipped with 4 doors and a 6 foot (short) box, remove left-rear tire/wheel.
5. Loosen clamp and disconnect rubber fuel fill hose at tank fitting. Using an approved diesel fuel holding tank, drain fuel tank through this fitting.