Tools You'll Likely Need:
* Wrench(es): Likely a socket wrench with the appropriate size sockets for the fuel line nuts and filter mounting bolts (check your manual). Line wrenches are preferred to avoid damaging the fuel lines.
* Fuel Line Disconnect Tool: This tool helps to disconnect fuel lines without damaging them. It's highly recommended.
* Jack and Jack Stands: For safer access to the filter.
* Rags or Shop Towels: To clean up any spilled fuel.
* New Fuel Filter: Ensure you get the correct filter for your vehicle. The part number will be in your owner's manual or from an auto parts store using your vehicle's information.
* Container: To catch the fuel draining from the lines. A suitable container is essential to catch spilled fuel.
* Gloves: Protect your hands.
* Safety Glasses: Protect your eyes.
* Torque Wrench (Optional but recommended): To ensure proper tightening of the fuel lines.
Steps:
1. Safety First: Disconnect the negative battery terminal.
2. Locate the Fuel Filter: Consult your repair manual to locate the fuel filter's exact position. It's usually found along the fuel line, somewhere between the fuel tank and the engine.
3. Prepare for Drainage: Place your container under the fuel filter to catch the spilled fuel.
4. Loosen Fuel Lines: Carefully loosen the fuel line clamps or nuts using line wrenches. Work slowly and carefully to avoid damaging the lines. You might need a fuel line disconnect tool to help separate the lines.
5. Release Fuel Pressure: Some vehicles require relieving fuel system pressure before disconnecting the fuel lines to avoid spraying fuel. Your repair manual will tell you how to do this safely. Methods may involve briefly cranking the engine until it stops or using a pressure release valve.
6. Remove the Fuel Filter: Once the fuel lines are disconnected, carefully remove the fuel filter from its mounting bracket.
7. Compare Old and New Filters: Compare the old filter's orientation to the new one to ensure you install the new filter correctly. Note the direction of fuel flow.
8. Install the New Fuel Filter: Install the new fuel filter, making sure it's oriented correctly.
9. Reconnect Fuel Lines: Carefully reconnect the fuel lines. Ensure the lines are securely attached.
10. Tighten Connections: Tighten the fuel line connections to the correct torque specification (consult your repair manual).
11. Reconnect Battery: Reconnect the negative battery terminal.
12. Check for Leaks: Inspect all connections for leaks. Start the engine and look for any signs of leaking fuel. Let the engine run for a few minutes to ensure the system primes properly.
13. Dispose of Old Filter Properly: Dispose of the old fuel filter according to local regulations.
Important Considerations:
* Fuel is highly flammable. Work in a well-ventilated area and avoid sparks or open flames.
* Fuel is toxic. Wear gloves and safety glasses.
* If you're uncomfortable performing this task yourself, take your vehicle to a qualified mechanic. Improperly installing a fuel filter can lead to serious problems.
This is a general guide, and specific steps may vary depending on your vehicle's setup. Always refer to a repair manual specific to your 1985 GMC High Sierra for detailed instructions and safety precautions. A Haynes or Chilton manual is a good investment for this type of work.
