Here's a general outline. This is not a substitute for a detailed repair manual specific to your year and engine. A Haynes or Chilton manual is highly recommended. Variations exist depending on your specific Blazer's configuration (engine type, fuel tank location, etc.).
1. Preparation:
* Safety First: Disconnect the negative battery terminal. Allow the fuel system to depressurize (several minutes of engine inactivity). Work in a well-ventilated area. Have a fire extinguisher handy.
* Gather Tools: You'll need jack stands, jack, socket set (various sizes), wrenches, fuel line disconnect tools, pliers, screwdrivers (possibly), safety glasses, gloves, rags, a new fuel pump (ensure it's the correct one for your vehicle), and possibly a fuel pump strainer.
* Consult your repair manual: It will provide specific torque specifications, component locations, and diagrams.
2. Accessing the Fuel Pump:
* Lower the Fuel Tank: This is usually the most difficult part. You'll likely need to:
* Raise the rear of the Blazer securely on jack stands.
* Locate the fuel tank straps. These are usually bolts or clips securing the tank to the frame.
* Carefully lower the tank. This may require disconnecting the fuel lines, vent lines, and possibly the fuel level sender wire. Support the tank with jack stands or a suitable support to prevent it from dropping suddenly.
* Alternative (some models): Access may be possible through an access panel in the bed of the truck, eliminating tank removal. Check your repair manual for this option.
3. Fuel Pump Replacement:
* Disconnect Fuel Lines: Carefully disconnect the fuel supply and return lines. Use fuel line disconnect tools to avoid damaging the lines or causing leaks. Have rags ready to absorb any spilled fuel.
* Disconnect Electrical Connector: Unplug the fuel pump electrical connector.
* Remove the Fuel Pump: The pump is typically secured to the fuel tank's top with a retaining ring or bolts. Consult your repair manual for the specific method.
* Install New Fuel Pump: Install the new fuel pump, ensuring a proper seal.
* Reconnect Everything: Carefully reconnect the fuel lines, electrical connector, and any other components removed.
4. Reassembly:
* Raise the Fuel Tank: Carefully raise the fuel tank back into its position, securing it with the straps.
* Reconnect Lines and Wires: Double-check all connections.
* Lower the Blazer: Carefully lower the Blazer from the jack stands.
* Reconnect the Battery: Reconnect the negative battery terminal.
5. Testing:
* Start the Engine: Check for leaks around the fuel lines and pump.
* Check for Fuel Pressure: If you have a fuel pressure gauge, check the fuel pressure to ensure the new pump is working correctly. (consult your repair manual for specifications)
* Test Drive: Take a short test drive to verify that the vehicle is running properly.
Important Considerations:
* Fuel Pressure: Before starting the replacement, it's a good idea (but not always necessary) to relieve fuel pressure in the system. Your repair manual will explain how to do this safely.
* Fuel Pump Strainer: The fuel pump strainer (sock) is usually located within the fuel tank. It's a good idea to replace this while you're replacing the pump to prevent future issues.
* Cleanliness: Keep everything clean to prevent debris from entering the fuel system.
This is a complex procedure. If you're not comfortable with this type of repair, it's strongly recommended to take your Blazer to a qualified mechanic. Improper installation can lead to significant damage or even injury. Always refer to your repair manual for detailed instructions and specific procedures for your vehicle.
