Because of the potential for fuel leaks and fire hazards, replacing the fuel filter is a task best left to someone experienced with auto repair unless you're very mechanically inclined and comfortable working with gasoline. Improper handling of fuel can lead to serious injury.
If you're determined to do it yourself, here's a general procedure. But again, proceed with extreme caution:
1. Safety First: Disconnect the negative battery cable. Work in a well-ventilated area, away from any open flames or sparks. Have appropriate safety glasses and gloves.
2. Locate the Filter: This is the most challenging step. You'll likely need to consult a repair manual specific to your 1986 Cadillac DeVille's engine (e.g., a Haynes or Chilton manual). These manuals usually have diagrams showing the fuel system and the filter's location. You might need to visually inspect fuel lines running from the tank towards the engine compartment.
3. Prepare for Replacement: Once you've located the filter, you'll need to gather tools including: wrench(es) appropriate for the filter's mounting (likely a line wrench or clamp-style wrench), rags, containers to catch spilled fuel (a pan, etc.), and possibly new fuel line clamps if the old ones are damaged.
4. Drain Fuel Pressure: This is crucial. There's pressure in the fuel lines; releasing it prevents fuel spraying when you disconnect the lines. Consult your repair manual on the proper method. It might involve a fuel pressure release valve.
5. Disconnect the Fuel Lines: Carefully loosen and remove the lines connecting to the fuel filter. Have your rags and containers ready to catch any spilled fuel.
6. Remove the Filter: Unscrew or unclamp the old fuel filter and remove it.
7. Install the New Filter: Carefully install the new filter, ensuring it's oriented correctly (there might be arrows indicating flow direction). Tighten the connections securely but avoid over-tightening.
8. Reconnect the Fuel Lines: Reconnect the fuel lines, making sure they are securely attached.
9. Reconnect the Battery: Reconnect the negative battery cable.
10. Check for Leaks: Start the car and check for any fuel leaks around the filter and connections. If you see leaks, stop immediately and re-tighten or replace any damaged components.
11. Dispose of the Old Filter Properly: Take the old filter to an auto parts store or recycling center for proper disposal.
Strong Recommendation: Unless you are very comfortable working on cars, especially with fuel systems, take your 1986 Cadillac Deville to a qualified mechanic to have the fuel filter replaced. The potential dangers associated with working on a fuel system are significant. The cost of having a professional do it is far less than the potential costs associated with an accident.
