Here's a general overview of the process. Specific steps may vary slightly depending on the engine (4.3L V6 or 5.3L V8) and trim level. Always consult a repair manual specific to your Blazer's year, engine, and trim for precise instructions and torque specifications.
1. Safety Precautions:
* Disconnect the negative battery terminal. This prevents accidental shorts and sparks.
* Ventilate the area. Work in a well-ventilated area away from any ignition sources.
* Wear safety glasses and gloves. Protect yourself from fuel and sharp metal.
* Have a fire extinguisher readily available.
2. Preparation:
* Gather your tools: You'll need a socket set (metric), wrenches, screwdrivers (Phillips and flathead), fuel line disconnect tools, jack, jack stands, wheel chocks, fuel pump pliers (or similar tool to remove the retaining ring), possibly a fuel pressure gauge, and a new fuel pump assembly (make sure it's the correct one for your vehicle).
* Lower the fuel tank: This is usually the most involved part. You'll need to access the tank straps and unbolt them to lower the tank. This often involves removing the access panel under the vehicle or possibly lowering the tank slightly from the rear for better access to the pump. Support the tank safely as you lower it. You might need to disconnect various electrical connectors and hoses related to the fuel level sender.
* Drain the fuel tank: Ideally, siphon out as much gas as possible to reduce the amount of fuel you're working with.
3. Fuel Pump Replacement:
* Access the fuel pump: Once the tank is lowered sufficiently, you'll locate the fuel pump assembly inside the tank. It's often held in place by a retaining ring.
* Disconnect the electrical connectors: Carefully disconnect the electrical connectors from the fuel pump and the fuel level sender.
* Remove the retaining ring: Use fuel pump pliers or a similar tool to carefully remove the retaining ring holding the fuel pump in place.
* Remove the fuel pump: Carefully lift the fuel pump assembly out of the tank.
* Install the new fuel pump: Reverse the removal process to install the new fuel pump assembly. Ensure the gasket is properly seated to prevent leaks.
* Reconnect the electrical connectors: Carefully connect all electrical connectors.
* Raise the fuel tank: Securely raise the fuel tank back into its position, reattaching all straps and connections.
4. Post-Installation:
* Reconnect the battery: Connect the negative battery terminal.
* Check for leaks: Carefully inspect all connections for leaks.
* Start the vehicle: Start the vehicle and check for any issues. It may take a few seconds for the pump to prime.
* Check the fuel pressure (optional): Using a fuel pressure gauge, verify the fuel pressure is within the manufacturer's specifications.
Important Considerations:
* Fuel pressure: Be aware of the potential for fuel pressure even after disconnecting the battery; allow sufficient time for pressure to bleed off.
* Fuel pump assembly: The fuel pump assembly usually includes the pump, strainer, and fuel level sender. Replacing the entire assembly is generally recommended.
* Repair manual: A repair manual specific to your vehicle is crucial. It will provide detailed diagrams, torque specifications, and safety information.
This is a simplified overview. The actual process can be more complex. If you are not comfortable performing this repair, it's best to consult a professional mechanic. Improperly installing a fuel pump can lead to safety hazards and vehicle damage.
