Fuel Return Line: Service and Repair

If replacement of a fuel feed, fuel return, or emission pipe is required, use welded steel tubing meeting GM Specification 124M, or its equivalent. The replacement pipe must utilize the same type of fittings as the original pipe to ensure the integrity of the connection.

NOTICE: Do Not use copper or aluminum tubing to replace steel tubing. Those materials do not have satisfactory durability to withstand normal vehicle vibrations. Only tubing meeting the 124M Specification is capable of meeting all the pressure and vibration characteristics necessary to ensure the durability standard required.

Always check and replace any "O" rings and/or washers that appear damaged.

Due to the fact that the fuel pipes are under high pressure on these systems, they require special consideration for service.

CAUTION: Do Not attempt to repair flexible fuel lines due to possible safety hazard. Replace only with the same type of flexible fuel lines and fittings as those removed.

PROCEDURE:

1. All fuel feed and return line attachments in the system except for return lines at the rear of the car, are screw type fittings.
2. Always use a back-up wrench when loosening or tightening the fittings.
3. Screw fittings used on the two systems utilize "O" rings for the fuel feed and return pipes and the two sizes of "O" rings are not interchangeable.
4. Anytime the fuel or return pipes are disconnected, inspect the "O" rings for cuts or other type of damage and replace as necessary.
5. The flare used on these fuel pipes is not compatible with the flare used on normal fuel pipes.
6. Use the correct torque when tightening these fittings.
7. If pipes are replaced, always use original equipment parts or parts that meet GM Specification 124M.
8. Damaged fuel hoses must be replaced. Do Not repair fuel hoses, other than by replacement.