Fuel Return Line: Service and Repair
ALL EXCEPT ALL WHEEL DRIVE
Fuel Lines - Front And Rear:
WARNING: To reduce the risk of fire and personal injury: DO NOT attempt to repair sections of nylon fuel lines. If damaged, replace. If nylon fuel feed or return lines become kinked, and cannot be straightened, they must be replaced.
Tools required: J 37088-A tool set, fuel line quick-connect fittings.
REMOVAL:
1. Relieve the fuel system pressure, refer to MAINTENANCE PROCEDURES/FUEL SYSTEM PRESSURE RELIEF.
2.Disconnect the quick-connect fittings at the engine compartment fuel feed and return lines:
a. Grasp both ends of one fuel line connection and twist 1/4 turn in each direction to loosen any dirt in the quick-connect fitting. Repeat for the other fittings.
WARNING: Safety glasses must be worn when using compressed air, as flying dirt particles may cause eye injury. Using compressed air, blow out the dirt from the quick-connect fittings before removing.
b. Choose the correct tool from the J 37088-A tool set for the size of the fitting.
c. Insert the tool into the female connector, then push inward to release the male connector.
d. Repeat for the other fitting.
3. Cap the fuel feed and return pipes.
CAUTION: If it is necessary to remove rust or burrs from the male tube end of a quick-connect fitting: use emery cloth in a radial motion with the tube to prevent damage to O-ring sealing surface.
^ Using a clean shop towel, wipe off male tube ends.
^ Check all connectors for dirt and burrs. Clean or replace components/assemblies as required.
4. Raise the vehicle on a hoist.
5. Grasp the fuel level meter fuel return tube and fuel return line fitting. Twist the quick-connect fitting 1/4 turn in each direction to loosen any dirt within the fitting. Repeat for the other fuel feed line fitting at the fuel filter.
6. Wearing safety glasses and using compressed air, blow the dirt out of the quick-connect fittings, and disconnect.
7. Cap the fuel level meter return tube and the in-line fuel filter outlet as needed.
8. Remove the fuel feed and return line attaching hardware and fuel feed and return lines.
^ Note the position of the fuel lines and hardware for installation.
INSTALLATION:
WARNING: To reduce the risk of fire and personal injury:
^ If nylon lines are nicked, scratched or damaged during installation, they must be replaced.
^ Before connecting fuel line fittings, always apply a few drops of clean engine oil to the male tube ends. This will ensure proper reconnection and prevent a possible fuel leak. (During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated).
1. Install new fuel feed and return lines and hardware as noted during removal.
2. Remove the caps from the in-line filter outlet and fuel level meter return tube.
3. Install the new plastic connector retainers on the filter outlet tube and on the fuel level meter return tube.
4. Connect the quick-connect fittings:
a. Apply a few drops of clean engine oil to both ends of the filter and the fuel level meter return tube.
b. Push the connectors together to cause the retaining tabs/fingers to snap into place.
c. once installed, pull on both ends of each connection to make sure they are secure.
5. Lower the vehicle.
6. Apply a few drops of clean engine oil to the male tube ends of the fuel feed and return pipes.
7. Connect the quick-connect fittings:
a. Push the connectors together to cause the retaining tabs/fingers to snap into place.
b. Once installed, pull on both ends of each connection to make sure they are secure..
8. Tighten the fuel filler cap.
9. Connect the negative battery cable.
10. Turn the ignition switch to the ON position for two seconds, and then turn OFF the ignition switch for five seconds. Again turn it ON and then check for fuel leaks.
11. The ECM will need to relearn the IAC valve pintle position following battery reconnection, refer to MAINTENANCE PROCEDURES/IDLE LEARN PROCEDURE.
ALL WHEEL DRIVE (AWD)
AWD Fuel And Vapor Lines:
WARNING: To reduce the risk of fire and personal injury: DO NOT attempt to repair sections of nylon fuel lines. If damaged, replace. If nylon fuel feed or return lines become kinked, and cannot be straightened, they must be replaced.
NOTE:
^ If nylon fuel feed or return lines become kinked, and cannot be straightened, they must be replaced.
^ When replacing fuel return connecting hose, always replace it with original equipment or parts meeting GM specifications, use only reinforced fuel-resistant hose which is identified with the word "Fluroelastomer" or "GM 6163-M" on the hose. Inside hose diameter must match outside pipe diameter.
REMOVAL:
^ Fuel level meters to the fuel filter.
1. Relieve the fuel system pressure, refer to MAINTENANCE PROCEDURES/FUEL SYSTEM PRESSURE RELIEF.
2. Drain the fuel tank, refer to MAINTENANCE PROCEDURES/DRAINING THE FUEL TANK.
3. Remove the fuel tank, refer to FUEL TANK AND FUEL LEVEL METER.
4. Locate the tank in a suitable work area away from heat, flame or other source of ignition.
^ Clean all fuel pipe and hose connections and surrounding areas before disconnecting to avoid possible contamination of the fuel system.
5. Disconnect the fuel return connecting hose and clamps from the fuel level meter assembly and secondary fuel level meter assembly return tubes.
6. Remove the rear fuel feed pipe assembly from the fuel level meter.
7. Remove the tape and rear fuel feed pipe assembly from the bushing.
8. Remove the rear fuel return pipe assembly from the secondary fuel level meter.
9. Remove the retaining strap from the fuel level meter return tube and the rear fuel return pipe assembly.
^ Note the position of the retaining strap for installation.
INSTALLATION:
1. Install the rear fuel return pipe assembly to secondary fuel level meter.
2. Position the new strap on the rear fuel return pipe assembly and fuel level meter return tube.
3. Connect the rear fuel feed pipe assembly to the fuel level meter.
4. Position the fuel level meter pipe assembly in the bushing and secure with tape.
^ Tighten the rear fuel feed and return pipe fittings to 27 Nm (20 lb.ft).
5. Install the fuel return connecting hose and clamps to the fuel level meter assembly and the secondary fuel level meter assembly return tubes.
6. Install the fuel tank.
7. Add fuel and install the fuel filler cap.
8. Connect the negative battery cable.
9. Turn the ignition switch ON for two seconds, then turn it OFF for five seconds. Again turn the ignition switch ON and check for fuel leaks.
10. The ECM needs to relearn the IAC valve pintle position, refer to MAINTENANCE PROCEDURES/IDLE LEARN PROCEDURE.
Engine compartment to fuel filter
Tools required: J 37988-A tool set.
WARNING: To reduce the risk of fire and personal injury: DO NOT attempt to repair sections of nylon fuel lines. If damaged, replace. If nylon fuel feed or return lines become kinked, and cannot be straightened, they must be replaced.
NOTE:
^ If nylon fuel feed or return lines become kinked, and cannot be straightened, they must be replaced.
REMOVAL:
1. Relieve the fuel system pressure, refer to MAINTENANCE PROCEDURES/FUEL SYSTEM PRESSURE RELIEF.
2. Disconnect the quick-connect fittings at the engine compartment fuel feed and return lines:
a. Grasp both ends of one fuel line connection and twist 1/4 turn in each direction to loosen any dirt in the quick-connect fitting. Repeat for the other fittings.
WARNING: Safety glasses must be worn when using compressed air, as flying dirt particles may cause eye injury. Using compressed air, blow out the dirt from the quick-connect fittings before removing.
b. Choose the correct tool from the J 37088-A tool set for the size of the fitting.
c. Insert the tool into the female connector, then push inward to release the male connector.
d. Repeat for the other fitting.
3. Cap the fuel feed and return pipes.
CAUTION: If it is necessary to remove rust or burrs from the male tube end of a quick-connect fitting: use emery cloth in a radial motion with the tube to prevent damage to O-ring sealing surface.
^ Using a clean shop towel, wipe off male tube ends.
^ Check all connectors for dirt and burrs. Clean or replace components/assemblies as required.
4. Raise the vehicle on a hoist.
5. Disconnect the fuel feed from the outlet side of the in-line filter.
6. Disconnect the fuel return line from the rear fuel return pipe assembly (near the in-line filter).
7. Remove the fuel feed and return line attaching hardware.
^ Note the position of the hardware for installation.
INSTALLATION:
1. Position the fuel feed and return lines and install with attaching hardware as noted during removal.
2. Connect the fuel return line to the rear fuel return pipe assembly (near the in-line fuel filter).
3. Connect the fuel feed line to the outlet side of the fuel filter, using a back-up wrench, tighten the fuel feed and return fittings to 27 Nm (29 lb.ft).
4. Lower the vehicle.
WARNING: To reduce the risk of fire and personal injury:
^ If nylon lines are nicked, scratched or damaged during installation, they must be replaced.
^ Before connecting fuel line fittings, always apply a few drops of clean engine oil to the male tube ends. This will ensure proper reconnection and prevent a possible fuel leak. (During normal operation, the O-rings located in the female connector will swell and may prevent proper reconnection if not lubricated).
5. Apply a few drops of clean engine oil to the male tube ends of the fuel feed and return lines.
6. Connect the fuel line quick-connect fittings:
a. Push the connectors together to cause the retaining tabs/fingers to snap into place.
b. Once installed, pull on both ends of each connection to make sure they are secure.
7. Tighten the fuel filler cap.
8. Connect the negative battery cable.
9. Turn the ignition switch to the ON position for two seconds, then turn it OFF for five seconds. Again turn it ON and check for fuel leaks.
10. The ECM will need to relearn the IAC valve pintle position following battery reconnection, refer to MAINTENANCE PROCEDURES/ IDLE LEARN PROCEDURE.