See Figures 1 and 2Gasoline Engines
The fuel filter is located behind the fuel inlet connection on the carburetor. On 1976-87 vehicles fuel filters incorporate a check valve and are not interchangeable with earlier years. Replace the fuel filter every 15,000 miles (24,135 km), or sooner if engine flooding is a problem.
- Using an open-end wrench (preferably a line or flare nut wrench), loosen the fuel line connection from the larger fuel filter nut. You will have to hold the other nut with a wrench to keep it from turning. Most of the time these units are quite difficult to remove. It is a good idea to apply a lot of penetrating oil to the threads and then tap the nut lightly.
- Once you have the fuel line disconnected from the carburetor, remove the larger nut from the carburetor with a box-end wrench or socket.
- Remove the filter element and spring from the carburetor.
- Check the element for blockage by blowing through the fuel inlet end. If the element is good, air should pass through easily.
- Once you have checked and/or replaced the filter, reinstall the carburetor nut and the fuel line. Be careful not to strip the threads.
On diesel engines the fuel filter is located at the back of the engine above the intake manifold between the mechanical fuel pump and the injection pump. The filter should be replaced at least every 30,000 miles (48,000 km). Disconnect the fuel lines from the filter, replace with a new filter and reconnect the fuel lines.