Here's a general outline. Specific steps might vary slightly depending on your Blazer's engine and trim level. Always consult a repair manual specific to your vehicle's year, make, and model for precise instructions and diagrams. A Haynes or Chilton manual is a good investment.
Before You Begin:
* Safety First: Disconnect the negative battery terminal. Work in a well-ventilated area, away from any ignition sources. Use proper safety glasses and gloves.
* Gather Supplies: You'll need jack stands, jack, socket wrench set (metric), various screwdrivers (Phillips and flathead), a fuel pump removal tool (often a specialized socket), new fuel level sensor, rags, and possibly a siphon pump to remove remaining fuel from the tank (if you're comfortable doing so). A fuel-resistant sealant may also be necessary.
* Fuel Removal (Optional but Recommended): If you're comfortable doing so, siphon or carefully drain as much fuel as possible from the tank. This reduces the risk of spillage and makes the job easier. Be extremely cautious when working near fuel.
General Steps:
1. Vehicle Preparation: Securely jack up the Blazer and place it on jack stands. Never work under a vehicle supported only by a jack.
2. Access the Fuel Pump: Locate the fuel pump access panel under the vehicle, usually in the rear passenger compartment. This usually involves removing some interior trim pieces and possibly a panel under the vehicle’s floor.
3. Remove Access Panel: Carefully remove the access panel, following any instructions provided in your repair manual.
4. Disconnect Electrical Connections: Disconnect the electrical connectors from the fuel pump and the fuel level sensor. Take note of their placement for reassembly.
5. Remove Fuel Pump (Usually Necessary): In most cases, you'll need to remove the fuel pump assembly to access the fuel level sensor. This usually involves using a fuel pump removal tool to unscrew the pump retainer from the fuel tank.
6. Access and Replace the Fuel Level Sensor: Once the fuel pump is out, you should be able to access the fuel level sensor. It's typically held in place with clips or screws. Carefully remove the old sensor.
7. Install the New Sensor: Install the new fuel level sensor, ensuring a proper seal.
8. Reassemble: Carefully reassemble the fuel pump assembly and reinstall it in the tank. Reconnect the electrical connectors.
9. Reinstall Access Panel: Securely reinstall the fuel pump access panel.
10. Lower Vehicle: Carefully lower the Blazer from the jack stands.
11. Check for Leaks: Inspect the area for any fuel leaks.
12. Reconnect Battery: Reconnect the negative battery terminal.
13. Test: Start the vehicle and check the fuel gauge to ensure it's functioning correctly.
Important Considerations:
* Fuel Pressure: Fuel pressure can build up in the lines. Always consult your repair manual for proper procedures to relieve pressure.
* Fuel Tank Pressure: Some fuel tanks may have slight pressure. Release any pressure before disconnecting lines.
* Repair Manual: A repair manual specific to your 1998 Chevy Blazer is crucial for detailed instructions and diagrams. This will significantly reduce the risk of error and damage.
If you are not comfortable performing this repair yourself, it is strongly recommended that you take your vehicle to a qualified mechanic. Working with fuel is dangerous, and improper repair can lead to serious damage or injury.
