Safety First!
* Disconnect the negative battery terminal. This is crucial to prevent sparks and potential explosions.
* Work in a well-ventilated area. Fuel fumes are dangerous.
* Wear safety glasses and gloves.
Tools and Materials You'll Need:
* New fuel pump: Make sure you get the correct one for your specific Blazer's engine (4.3L, 5.7L, etc.). Get the pump assembly, which usually includes the sending unit and filter.
* Fuel pump socket: This is a special socket designed to remove the retaining ring around the fuel pump. The size varies depending on the year and model, so confirm the correct size before purchasing.
* Socket wrench and ratchet: To use with the fuel pump socket.
* Wrench set: Various sizes will likely be needed for disconnecting fuel lines and other components.
* Screwdrivers (Phillips and flathead): For removing access panels and possibly other fasteners.
* Fuel line disconnect tools: These make disconnecting the fuel lines much easier and prevent damage.
* Jack and jack stands: To safely lift the vehicle.
* Torque wrench: To properly tighten bolts and nuts to the manufacturer's specifications.
* Shop rags or absorbent material: To clean up any spilled fuel.
* New fuel filter (if applicable): Consider replacing this while you're at it.
* Fuel line clamps: If you're replacing sections of fuel line.
* Safety glasses and gloves: Protect yourself.
Steps:
1. Prepare the vehicle: Park on a level surface, engage the parking brake, and chock the wheels. Disconnect the negative battery terminal.
2. Lower the fuel tank: This is the most challenging part. Consult a repair manual specific to your Blazer's year and engine for detailed instructions. Generally, this involves:
* Accessing the fuel pump: This usually involves removing access panels under the vehicle, often near the rear passenger side. Consult your repair manual.
* Lowering the tank: This might require disconnecting the fuel filler neck, fuel lines, and possibly the fuel tank straps. Support the tank properly to prevent damage. Use jack stands to keep the tank supported at all times. Some Blazers might require disconnecting the exhaust system for better access.
3. Disconnect the fuel lines: Use fuel line disconnect tools to carefully separate the fuel lines from the fuel pump. Have rags ready to absorb any spilled fuel. Note the order of connection if you need to reference it.
4. Remove the fuel pump: Remove the retaining ring using the fuel pump socket and ratchet. Then carefully lift out the old fuel pump assembly.
5. Install the new fuel pump: Compare the new pump to the old one to ensure everything lines up correctly. Install the new assembly, carefully replacing the retaining ring and ensuring a secure fit.
6. Reconnect the fuel lines: Carefully attach the fuel lines, making sure they are securely connected and tightened.
7. Raise the fuel tank: Slowly raise the fuel tank back into place, reconnecting any necessary components.
8. Reconnect the battery terminal.
9. Prime the fuel system: This often requires cranking the engine for a few seconds without starting it until the fuel pump primes the system. Your repair manual will confirm how your system primes.
10. Check for leaks: After starting the engine, carefully check all fuel lines and connections for any leaks.
Important Considerations:
* Repair Manual: A repair manual specific to your 1999 Chevy Blazer is essential. It will provide detailed diagrams, torque specifications, and step-by-step instructions.
* Professional Help: If you're not comfortable working with fuel systems or feel unsure about any step, consider seeking professional help from a qualified mechanic. Working with fuel is dangerous.
* Fuel Pressure: After installation, you might need to check the fuel pressure to ensure the new pump is working correctly.
This is a general overview. Always refer to a repair manual specific to your vehicle for detailed instructions and safety precautions. Attempting this repair without the proper knowledge and tools can be dangerous and lead to damage to your vehicle.
