Here's a general outline of the process. This is not a complete, step-by-step guide, and specific procedures may vary slightly depending on the exact engine and equipment. Always consult a repair manual specific to your 1999 Cadillac Seville for detailed instructions, diagrams, and torque specifications.
Safety First:
* Disconnect the negative battery terminal before starting any work on the fuel system.
* Work in a well-ventilated area. Fuel vapors are highly flammable.
* Wear safety glasses and gloves.
* Have a fire extinguisher readily available.
* Consider using fuel-resistant tools and materials.
General Steps (Consult your repair manual for precise details):
1. Prepare the Vehicle: Raise and securely support the vehicle on jack stands. You'll need access to the fuel tank, typically located under the rear of the car.
2. Access the Fuel Tank: This usually involves removing access panels or possibly lowering the fuel tank itself (often requiring the removal of fuel lines, sending unit wires, and possibly the exhaust). Consult your repair manual for specific instructions for this model.
3. Release Fuel Pressure: This is crucial to prevent fuel spraying during the procedure. The method for releasing fuel pressure varies depending on the year and model, consult your repair manual to safely release the fuel system pressure. This may involve disconnecting the fuel pump relay or using a fuel pressure release tool.
4. Disconnect Fuel Lines and Electrical Connections: Carefully disconnect the fuel lines from the fuel pump module. Be prepared for some fuel spillage. Use clean rags to absorb any fuel. Also disconnect the electrical connectors to the fuel pump and level sensor. Mark the connections for correct reassembly.
5. Remove the Fuel Pump Module: This usually involves unbolting the retaining ring and lifting the fuel pump assembly out of the tank. This step often involves using special tools to secure and remove the assembly as one unit.
6. Replace the Fuel Pump: Carefully examine the old pump to understand how it fits and which components need to be transferred to the new pump (o-rings, gaskets, etc.). Install the new fuel pump assembly, ensuring everything seats correctly.
7. Reassemble: Carefully reverse the removal process, ensuring all fuel lines, electrical connections, and fasteners are properly secured and tightened to the correct torque specifications (found in your repair manual).
8. Reconnect the Battery: Reconnect the negative battery terminal.
9. Prime the Fuel System: Before starting the engine, you may need to prime the fuel system (consult your repair manual). This could involve turning the ignition key to the "on" position without starting the engine several times or using a scan tool to prime the pump.
10. Test: Start the engine and check for leaks. Monitor the fuel pressure if you have a gauge.
Important Considerations:
* Repair Manual: A repair manual specific to your 1999 Cadillac Seville is absolutely essential. Generic instructions are insufficient for this task.
* Tools: You'll need various tools, including wrenches, sockets, screwdrivers, possibly a fuel pump removal tool, and possibly a fuel pressure gauge.
* Parts: Ensure you obtain the correct fuel pump for your specific engine. Consider replacing the fuel filter while you're at it.
This process is significantly more involved than a simple description can convey. If you're uncomfortable performing this repair yourself, take your vehicle to a qualified mechanic. Working on the fuel system is inherently risky, and a mistake could lead to injury or fire.
