1. Safety First:
* Disconnect the battery: This is crucial to prevent sparks that could ignite fuel vapors. Disconnect the negative (-) terminal first.
* Ventilate the area: Work in a well-ventilated area or outdoors. Fuel vapors are extremely flammable.
* Use proper safety equipment: Wear safety glasses and gloves. Consider a respirator if you anticipate a lot of fuel vapor exposure.
* Have a fire extinguisher handy: A Class B fire extinguisher (for flammable liquids) should be readily available.
2. Preparation:
* Locate the fuel pump access panel: This is usually located under the rear passenger seat, but it could be in the bed of a Blazer if it's a truck version. Consult your repair manual for the exact location. You might need to remove the rear seat or access panel to reach the fuel tank.
* Gather your tools: You'll need sockets, wrenches (possibly a fuel line disconnect tool), a fuel pump pliers or a similar tool for the retaining ring on the pump, and possibly a sealant for the access panel if it's not reusable. You may also need a siphon pump to remove remaining fuel from the tank, which is highly recommended.
* Drain the fuel tank (highly recommended): Use a siphon pump to remove as much fuel as possible from the tank. This significantly reduces the risk of fuel spillage and makes the job easier and safer. You can carefully lower the fuel level with a siphon, but you might need to take the fuel to an authorized recycling center or gas station.
3. Removal Process:
* Disconnect the electrical connector: Unplug the electrical connector from the fuel pump.
* Disconnect the fuel lines: Carefully disconnect the fuel lines using the appropriate tool, avoiding any spills. There will likely be a fuel feed and a return line. Some vehicles have quick-disconnect fittings; others may require line wrenches. Have rags ready to absorb any drips.
* Remove the fuel pump access panel: Carefully remove the access panel, taking note of how it's secured.
* Remove the retaining ring: Use fuel pump pliers or a similar tool to remove the retaining ring holding the fuel pump assembly in place. This step can vary depending on your vehicle's design.
* Lift out the fuel pump assembly: Carefully lift the fuel pump assembly out of the tank. This can be heavy, so be prepared.
* Disconnect any remaining parts: Disconnect any other lines or components attached to the fuel pump assembly.
4. Installation (Reverse of Removal):
Follow the steps in reverse order to install the new fuel pump. Make sure to:
* Use a new sealing gasket: If one is provided with the new fuel pump.
* Securely reconnect all fuel lines and electrical connectors: Double-check everything.
* Securely reinstall the access panel: Ensure the seal is proper to prevent leaks.
Important Notes:
* Consult a repair manual: A repair manual specific to your 1999 Chevy Blazer is highly recommended. It will provide detailed diagrams, torque specifications, and other crucial information.
* Consider professional help: If you're not comfortable performing this repair yourself, take your Blazer to a qualified mechanic. Working with fuel systems is dangerous if not done properly.
This process is a general guideline. Specifics may vary slightly depending on the exact model of your 1999 Blazer. Always prioritize safety and consult your vehicle's repair manual for the most accurate instructions.
