Here's a general overview of the process. Again, this is not a substitute for a proper repair manual.
1. Safety First!
* Disconnect the negative battery terminal. This is crucial to prevent electrical shorts and sparks.
* Work in a well-ventilated area. Gasoline fumes are highly flammable and dangerous.
* Wear safety glasses and gloves.
2. Preparation:
* Locate the fuel pump. It's typically located inside the fuel tank. Your repair manual will show you the exact location and access points.
* Gather your tools. You'll need various tools, including sockets, wrenches, screwdrivers, possibly a fuel pump removal tool, and a fuel line disconnect tool. The repair manual will specify the exact tools.
* Obtain a new fuel pump. Ensure it's the correct part number for your 1999 Cadillac DeVille.
3. Accessing the Fuel Pump:
* Lower the fuel tank. This usually involves dropping the tank from underneath the vehicle. This may require disconnecting fuel lines, electrical connectors, and possibly the fuel tank straps. This is the most challenging part of the job. Your repair manual will have detailed instructions.
* Some models might have access through a trap door in the trunk or under the rear seat, simplifying access; check your manual.
4. Fuel Pump Replacement:
* Disconnect the fuel lines. Use a fuel line disconnect tool to carefully separate the lines. Be prepared for some fuel spillage; have absorbent materials ready.
* Disconnect the electrical connector. Carefully disconnect the electrical connector to the fuel pump.
* Remove the fuel pump assembly. This may involve removing retaining rings, bolts, or a locking ring. The repair manual will detail this step.
* Install the new fuel pump assembly. Carefully reverse the removal process to install the new fuel pump. Ensure all seals and gaskets are in place.
* Reconnect the electrical connector and fuel lines. Double-check everything is secure and properly connected.
5. Reassembly:
* Raise the fuel tank. Securely reattach the fuel tank and its straps.
* Reconnect the negative battery terminal.
* Prime the fuel system. Your repair manual will explain how to do this; it's often done by cranking the engine (without starting) for a few seconds.
* Check for leaks. Carefully inspect all connections for leaks before starting the engine.
6. Test and Verify:
* Start the engine. Listen for any unusual noises from the fuel pump.
* Check for fuel leaks. Inspect the area around the fuel tank and lines.
* Test drive the vehicle. Observe the vehicle's performance to ensure the fuel pump is working correctly.
Disclaimer: This is a simplified overview. Attempting this repair without the proper knowledge, tools, and a repair manual specific to your vehicle is strongly discouraged. Incorrect installation can result in serious injury or damage to your vehicle. If you are not comfortable performing this repair yourself, it's best to take your vehicle to a qualified mechanic.
