Chassis Fuel Return

Chassis Fuel and Vapor Pipes:

NOTE:
- When replacing fuel or EVAP pipes, always replace them with original equipment or parts that meet the GM specifications for those parts. The replacement pipes must have the same type of fittings as the original pipes to ensure the integrity of the connection.
- Do not use copper or aluminum tubing to replace steel tubing. Only tubing meeting the 124-M specification or its equivalent is capable of meeting all pressure, corrosion and vibration characteristics necessary to ensure the durability standard required.
- When repairing fuel or EVAP pipes with hoses, always replace them with original equipment or parts meeting GM specifications. Use only reinforced fuel-resistant hose which is identified with the word "Fluornelastomer" or "GM 6163-M" on the hose. Inside hose diameter must match outside pipe diameter.
- Do not use rubber hose within 100 mm (4") of any part of the exhaust system or within 254 mm (10") of the catalytic converter.
- A minimum of 13 mm (1/2") clearance must be maintained around sharp edges such as flanges, pinch welds, etc., to prevent contact and chaffing. A minimum of 19 mm (3/4") clearance must be maintained around all moving parts.
- If more than a 200 mm (6") length of pipe is removed, use a combination of steel pipe and hose so that the total hose lengths, including the 100mm (4") additional length will not be more than 254 mm (10") long. Follow the same routing as the original pipe.
- Cut ends of pipe remaining on car square with a tube cutter. Using the first step of a double flaring tool, form a head on the end of both pipe sections. If pipe is too corroded to withstand the beading operation without damage, the pipe should be replaced. If a new section of pipe is used, form a bead on both ends of it also.
- Use screw type hose clamps. Slide clamps onto pipe and push hose 51 mm (2") onto each portion of fuel pipe.

REMOVE OR DISCONNECT
1. Negative battery cable.
2. Relieve fuel system pressure.

Clean
Clean all fuel and EVAP pipe/hose connections and surrounding areas before disconnecting to avoid possible contamination of the fuel system.

3. Raise vehicle.
4. Engine compartment connecting fuel feed, return, and EVAP pipe assemblies from chassis fuel pipes.
5. Fuel feed pipe from outlet side of in-line fuel filter.
- Discard 0-ring.
6. Fuel return and EVAP pipes from rear fuel pipes.
7. Fuel pipe attaching hardware and fuel pipes from under body.
- Note position of fuel pipes for installation.

Inspect
Pipes for bends, kinks and cracks. Repair or replace pipes as required.

INSTALL OR CONNECT
1. Position new or repaired fuel pipe or pipes in body clips as noted during removal and install with attaching hardware.
2. Position new 0-ring on fuel feed pipe and connect to outlet side of in-line fuel filter.

Tighten
Fitting to 30 Nm (22 lb. ft.).

3. Fuel return and EVAP pipes to rear fuel pipes.
4. Chassis fuel pipes to engine compartment connecting fuel pipes.
5. Lower vehicle.
6. Tighten fuel filler cap.
7. Negative battery cable.

INSPECT
Turn ignition switch to "ON" position for two seconds, then turn to "OFF" for ten seconds. Again turn to "ON" position and check for fuel leaks.