GM Full-Size Trucks 1980-1987 Repair Guide

Gasoline Fuel Filter


To reduce the chance of personal injury, cover the fuel line with cloth to collect the fuel and then place the cloth in an approved container.

There are three types of fuel filters; internal (in the carburetor fitting), in-line (in the fuel line) and in-tank (the sock on the fuel pickup tube).


Before removing any component of the fuel system, refer to the Fuel Pressure Release procedures in this section and release the fuel pressure.

Carbureted Engines

Internal filters are located in the inlet fitting on all carburetors. Elements are placed in the inlet hole with the gasket surface outward. A spring holds the element outward, sealing it by compressing a gasket surface against the inlet fitting. A check valve is also built into the filter element.

  1. Make sure the ignition is off.
  3. Relieve fuel system pressure by unscrewing the fuel tank cap.

See Figures 1, 2, 3 and 4

Click image to see an enlarged view

Fig. Fig. 1: Use a suitable line wrench to disconnect the fuel line from the carburetor fuel inlet nut

  1. Disconnect fuel line connection at fuel inlet filter nut.

Click image to see an enlarged view

Fig. Fig. 2: Loosen the fuel inlet nut using the proper size line wrench or socket

  1. Remove fuel inlet filter nut from carburetor. Using a line wrench will prevent the flats on the nut from rounding during removal and tightening.