Before you begin:
* Safety First: Disconnect the negative battery cable. This prevents accidental sparks. Work in a well-ventilated area away from any open flames or ignition sources. Use appropriate safety glasses and gloves.
* Fuel Safety: You'll need to relieve pressure in the fuel system. Consult your owner's manual for the proper procedure. This often involves disconnecting the fuel pump relay or fuse. Allow ample time for fuel pressure to bleed off before proceeding.
* Gather Tools: You'll likely need: socket wrench set (metric), various screwdrivers (Phillips and flathead), pliers, a fuel pump removal tool (sometimes specialized), a shop rag or absorbent material to clean up any spilled fuel, and a new fuel sending unit. You might also need a pry bar or similar tool depending on access.
* Consult Repair Manual: A repair manual specific to your 1999 Chevrolet Silverado is highly recommended. It will provide detailed instructions, diagrams, and torque specifications for your particular model.
General Steps (This is a simplified overview. Refer to your repair manual for precise instructions):
1. Access the Fuel Tank: This typically involves lowering the fuel tank. The method varies depending on the specific Silverado model (1500, 2500, etc.) and bed configuration (short bed, long bed). You may need to remove parts such as the bed liner, access panel, or even the rear bumper to gain access. Consult your repair manual.
2. Disconnect Fuel Lines: Once you have access to the fuel tank, carefully disconnect the fuel lines. Use a rag to absorb any spilled fuel. You may need specialized tools to disconnect quick-connect fittings. Mark the lines clearly to ensure correct reassembly.
3. Disconnect Electrical Connectors: Disconnect the electrical connectors from the fuel sending unit. Again, mark their positions for proper reconnection.
4. Remove the Fuel Sending Unit: This is where a fuel pump removal tool often comes in handy. The sending unit is usually secured by a retaining ring or clamp. Carefully remove the unit, paying attention to how it's assembled.
5. Install the New Fuel Sending Unit: Carefully install the new fuel sending unit, ensuring it's properly seated. Reconnect the electrical connectors and fuel lines.
6. Reinstall the Fuel Tank: Carefully reinstall the fuel tank. Make sure all connections are secure before tightening bolts.
7. Reconnect Battery: Reconnect the negative battery cable.
8. Check for Leaks: Before driving, carefully inspect for fuel leaks around the fuel lines and sending unit.
9. Start Vehicle: Start the vehicle and check the fuel gauge to ensure it's functioning correctly.
Important Notes:
* Fuel System Pressure: Failure to properly relieve fuel system pressure before working on the fuel tank is extremely dangerous.
* Fuel Spills: Take extreme care to prevent fuel spills. Spilled fuel is a fire hazard.
* Repair Manual: A repair manual is indispensable for this job. It will provide specific details relevant to your vehicle's model and year.
* Professional Help: If you're not comfortable performing this repair yourself, take your vehicle to a qualified mechanic.
This is a general outline; the specifics will vary depending on your truck's configuration. Always consult a repair manual for your specific 1999 Chevrolet Silverado model before attempting this repair. Safety should always be your top priority.
