Here's a general outline of the process. Always consult a repair manual specific to your 1999 Chevy Z71 for detailed instructions, torque specifications, and safety precautions. These instructions vary slightly depending on the engine (e.g., 4.3L, 5.7L).
1. Safety First:
* Disconnect the negative battery terminal. This is crucial to prevent sparks and electrical shock.
* Work in a well-ventilated area. Gasoline fumes are highly flammable and dangerous.
* Use safety glasses and gloves.
2. Prepare the Vehicle:
* Park on a level surface and engage the parking brake.
* Gather your tools: This will include sockets, wrenches, screwdrivers (likely Phillips and flathead), a fuel pump removal tool (often a special strap wrench), jack stands (essential for safety), jack, fuel line disconnect tool, new fuel filter (often replaced at the same time), new fuel pump assembly, rags, and possibly a fuel pressure gauge. You'll likely need a fuel pump retaining ring pliers.
* Lower the fuel tank: This is the most labor-intensive part. You'll need to access the fuel tank straps, likely located under the truck bed. Consult your repair manual for precise location and removal procedure. Support the tank adequately while disconnecting it. Some models require dropping the spare tire and other components.
3. Accessing the Fuel Pump:
* Once the tank is lowered (or partially lowered, depending on your truck's design): You'll find the fuel pump assembly on top of the tank. It is usually covered by a retaining ring (or a cover).
* Remove the retaining ring: Use the correct tool (often a specific fuel pump retaining ring pliers to avoid damage).
4. Disconnecting the Fuel System:
* Disconnect the electrical connector: Carefully unplug the electrical connector from the fuel pump.
* Disconnect the fuel lines: Use a fuel line disconnect tool to safely separate the fuel lines from the pump assembly. Have rags ready to soak up any spilled fuel. Be extremely careful to avoid sparks or open flames.
* Disconnect the fuel level sender (if applicable): This is a float that measures the fuel level.
5. Removing and Installing the Fuel Pump:
* Remove the fuel pump assembly: The pump may be held in place by a retaining ring, bolts, or a combination. Your repair manual will have detailed instructions.
* Install the new fuel pump assembly: Make sure the new pump assembly is correctly oriented.
* Reconnect everything: Reattach the fuel lines, fuel level sender, and electrical connector. Ensure all connections are secure and tight.
6. Reassembly:
* Raise the fuel tank: Carefully raise the fuel tank back into its original position.
* Reconnect the fuel tank straps: Make sure everything is secure.
* Reconnect the negative battery terminal.
7. Post-Installation:
* Check for leaks: Carefully inspect all connections for leaks.
* Start the vehicle: Listen for unusual noises and check the fuel gauge.
* Run the engine for several minutes: This allows the fuel system to prime itself.
Crucial Considerations:
* Fuel Pressure: A fuel pressure gauge can help ensure the fuel system is functioning correctly after the repair.
* Repair Manual: A factory service manual is invaluable for this repair. It provides precise details specific to your vehicle's year, make, and model.
* Professional Help: If you're unsure about any step, it's always best to seek professional help from a qualified mechanic. This is a complex repair with potential for serious consequences if done improperly.
This is a simplified overview. The actual process might be more complex depending on your specific Z71's configuration. Always refer to your vehicle's repair manual for detailed, accurate, and safety-conscious instructions. Remember safety is paramount when working with gasoline and automotive systems.
