Steps Involved (General):
1. Safety First: Disconnect the negative battery terminal. This will prevent electrical shocks and accidental sparking. Work in a well-ventilated area, away from any ignition sources. Fuel is highly flammable.
2. Prepare the Vehicle: Raise the rear of the Blazer securely using jack stands. Never work under a vehicle supported only by a jack.
3. Remove Access Panels: You'll likely need to remove some underbody panels or trim pieces to access the fuel tank straps and lines. The exact location and method will vary depending on your trim level and whether you have a 2WD or 4WD Blazer. Your repair manual will provide detailed instructions.
4. Disconnect Fuel Lines: Carefully disconnect the fuel lines leading to the tank. You will likely need fuel line disconnect tools to prevent damage. Be prepared for some fuel spillage. Use absorbent rags or cloths to soak up any leaks. You may need to relieve pressure in the fuel system beforehand (consult your repair manual).
5. Disconnect Electrical Connections: Disconnect the electrical connector(s) for the fuel pump sending unit and fuel pump.
6. Detach Fuel Tank Straps: Carefully release and remove the straps securing the fuel tank to the vehicle. These might be bolts or clips.
7. Lower the Fuel Tank: Slowly lower the fuel tank. This may require some maneuvering as it's relatively heavy and could be awkward to handle.
8. Access the Fuel Pump: Once the tank is lowered, you'll typically find the fuel pump assembly located at the top of the tank. It’s usually secured with a retaining ring. This ring will need to be carefully removed to access the fuel pump.
9. Remove and Replace the Fuel Pump: Remove the old fuel pump and install the new one, ensuring everything is correctly seated.
10. Reassembly: Carefully reverse the steps to reassemble everything, ensuring all connections are secure. Double-check the fuel lines for leaks before lowering the tank completely.
11. Lower the Fuel Tank: Securely mount the fuel tank.
Crucial Considerations:
* Repair Manual: A repair manual specific to your 2004 Chevy Blazer is absolutely essential. It will provide detailed diagrams, torque specifications, and safety precautions.
* Tools: You'll need a variety of tools, including jack stands, sockets, wrenches, fuel line disconnect tools, and possibly a fuel tank strap wrench.
* Fuel Safety: Handle fuel with extreme care. Avoid sparks, open flames, and smoking. Use proper ventilation.
* Professional Help: If you are not comfortable performing this repair yourself, take it to a qualified mechanic. This is a complex job with potential safety hazards.
This is a simplified overview. The actual process is more involved and potentially hazardous if not performed correctly. Always prioritize safety and consult a repair manual before attempting this repair.
