Here's a general procedure. Specifics might vary slightly depending on your Blazer's configuration. Consult a repair manual specific to your vehicle year and engine for detailed diagrams and instructions.
Tools you'll likely need:
* Wrench(es): Appropriate sizes to fit the fuel line clamps (likely line wrenches are best to avoid damaging the lines).
* Socket set: Possibly needed for removing the fuel pump access panel or retaining bolts.
* Shop rags or absorbent material: To clean up any spilled fuel.
* Safety glasses: To protect your eyes.
* Gloves: To protect your hands.
* Fuel line disconnect tool: This tool can help avoid damaging the quick-connect fittings. While not strictly necessary, it is highly recommended.
* Container: To catch any spilled fuel.
Procedure:
1. Safety First: Disconnect the negative battery terminal. Allow several minutes for the fuel system to depressurize.
2. Locate the Fuel Pump: This is typically under the rear seat or in the bed of the truck depending on your specific model. You might need to remove the rear seat or parts of the bed's interior. A repair manual will pinpoint the location.
3. Access the Fuel Pump: Once located, you'll likely need to remove an access panel or other components to reach the fuel pump.
4. Disconnect Electrical Connections: Carefully disconnect the electrical connectors from the fuel pump. Take note of their position for easy reassembly.
5. Disconnect Fuel Lines: This is the most critical step. There will be at least two lines:
* Fuel Supply Line: This line carries fuel *to* the engine.
* Fuel Return Line: This line carries excess fuel *back* to the tank.
* Using the Correct Tool: Use a fuel line disconnect tool, if you have one, to carefully separate the lines from the fuel pump. These lines typically have quick-connect fittings. If you don't have the tool, carefully pry them apart, but be gentle to avoid breaking the plastic fittings. Avoid using excessive force.
* Clamp Style Connections: Some vehicles may use clamps instead of quick-connects. If so, carefully loosen the clamps with the appropriate wrench and gently separate the fuel lines.
6. Collect Spilled Fuel: Be prepared for some fuel to leak during this process. Have absorbent rags or a container ready to soak it up immediately.
7. Remove the Fuel Pump: Once the fuel lines and electrical connections are disconnected, you can remove the fuel pump assembly itself. The method for this varies depending on the Blazer's design. Again, a repair manual is crucial here.
Important Considerations:
* Fuel Pressure: Even after disconnecting the battery, some pressure may remain in the fuel system. Be cautious.
* Fuel is Flammable: Work in a well-ventilated area, away from any open flames or sparks.
* Repair Manual: A repair manual specific to your 1999 Chevrolet Blazer ZR2 is strongly recommended. It will provide detailed diagrams, torque specifications, and other crucial information. This is not a job for the inexperienced without proper guidance.
If you are uncomfortable performing this repair yourself, it's best to take your Blazer to a qualified mechanic. Working on the fuel system improperly can be dangerous.
