The fuel tank must be removed to replace the fuel pump.
The instructions below are for removing the fuel tank from the car and removing the fuel pump assembly from the tank.
Fuel pump replacement instructions can be found here. You will need them once you have the fuel pump assembly out of the tank.
Removal of the gas tank:
Preparation is important! Use extreame care when dealing with gasoline. Always work in a well ventelated area. Have a fire extinguisher handy.
- Disconnect battery leads.
- Place wheel chocks on rear side of front tires.
- Loosen lugnuts on rear tires.
- To remove gasolene from fuel tank, insert a 3/8" hose into filler neck and siphon the gasolene into a fuel storage container.
- Using floor jack raise one side high enough to place jack stand, at lowest level, under jack placement on body.
- On opposite side of car, raise with floor jack to the lowest level of jack stand. Raise floor jack to 2 to 3 notches on jack stand.
- Go to opposite side of car and raise, the car to 2 to 3 notches on jack stands. Continue raising jack stands until car is 16" to 18" off floor and body is level.
- Spray PB Blaster on strap bolts. Repeat 4-5 applications, over a 24 hour period, to ease the removal of the strap bolts.
- Remove rear tires for accessibility of fuel tank and fuel lines.
- Remove rear stabilizer bar.
- Remove filler hose and overflow hose from the fuel tank. Stuff a rag in the fuel neck to minimize fuel vapors from escaping.
- Cut a 2X4 approx 12" and attach to head mount of floor jack. This will allow lowering the fuel tank without sliding off jack.
- Raise floor jack to 10"-12" from rear of fuel tank. The front will be supported by the tank straps.
- Loosen and remove strap bolts. Allow straps to fall to floor.
- Place a pan below fuel neck to catch any fuel that may spill out.
- Slowly lower tank until it has dropped 7"-8". Reach above fuel tank and disconnect electrical connector to fuel pump.
- Reach through drivers side rear wheel well to disconnect fuel lines. Us a 19MM and a 5/8" flare nut wrenches to separate connectors.
- Mark fuel lines as to send and return.
- Slowly lower floor jack. The front side of fuel tank will slide down the fuel tank straps.
Replace the fuel pump assembly:
- Tap the prongs, with a screwdriver and small hammer, on fuel pump mount counter-clockwise until latching prongs can be lifted up through slots.
- Slowly lift pump out of tank.
Take great care when removing the pump not to damage the gas gauge sending unit float or the connectors.
- Replace "O" ring when reinstalling fuel pump assembly. Available at Buick dealerships parts department.
- Place "O" ring around the opening.
- Carefully lower float through opening.
- Ensure "O" ring is laying in the opening.
- Lower fuel pump until mounting plate meets "O" ring.
- Rotate fuel pump assembly until the fuel lines are pointing in the original direction.
- Rotate fuel pump assembly counter-clock wise until tabs and slots line up.
- Drop tabs through slots while starting to depress "O" ring.
- Tap the tabs in a clockwise rotation until tabs meet the stop.
Reinstalling the fuel tank:
- Reverse the removal process.
- "O" rings are used in the fuel line connectors, remove the old "O" rings and insert new "O" rings. Purchase these "O" rings at a Buick dealership parts department. Both "O" rings are a total under $4.00.