Here's a general outline of the process. Consult a repair manual specific to your 1999 Mercury Sable station wagon for detailed instructions, diagrams, and torque specifications. These instructions can vary slightly depending on engine and trim level.
1. Safety First: Disconnect the negative battery cable. Allow several minutes for any residual electrical charge to dissipate.
2. Prepare the Vehicle: Raise the rear of the vehicle securely using jack stands. Never work under a vehicle supported only by a jack.
3. Locate the Fuel Tank: The fuel tank is typically located under the rear passenger compartment.
4. Drain the Fuel Tank: This is crucial. Use a siphon pump or drain valve to remove as much fuel as possible. This significantly reduces the risk of spills and makes the tank lighter to handle. Dispose of the fuel properly according to local regulations.
5. Remove Fuel Lines and Electrical Connections: Carefully disconnect the fuel lines (at least two—supply and return) and electrical connectors to the fuel pump. You'll need fuel line disconnect tools for this; avoid damaging the lines.
6. Remove Fuel Tank Straps and Access Panel (if applicable): Locate and remove the straps or bolts securing the fuel tank to the vehicle. Some models may require removal of an access panel to reach the tank straps.
7. Lower the Fuel Tank: Carefully lower the fuel tank. This may require support from a helper, especially with a full tank.
8. Access the Fuel Pump: Once the tank is lowered sufficiently, you'll be able to access the fuel pump assembly. This typically involves removing a retaining ring or cover.
9. Replace the Fuel Pump: Once the old pump is out, install the new pump, ensuring all seals and gaskets are properly in place.
10. Reassemble Everything: Reverse the removal process, ensuring all fuel lines, electrical connections, and tank straps are securely reconnected. Tighten all fasteners to the correct torque specifications (see repair manual).
11. Lower the Vehicle: Carefully lower the vehicle from the jack stands.
12. Reconnect the Battery: Reconnect the negative battery cable.
13. Check for Leaks: Carefully inspect all connections for leaks before starting the engine.
14. Prime the Fuel System (Possibly): You might need to prime the fuel system by turning the ignition key to the "on" position for several seconds several times before attempting to start the engine. Refer to your repair manual.
Again, this is a general overview. Using a repair manual specific to your 1999 Mercury Sable is absolutely critical for accurate and safe completion of this task. If you are not comfortable performing this repair yourself, take your vehicle to a qualified mechanic. Working with fuel systems requires careful attention to safety; mistakes can be dangerous.
