REMOVAL & INSTALLATION
Carburetor Mounted Filters
See Figures 1 and 2
Several different types of carbureted-mounted filters are used. Some filters screw into the float chamber with a rubber fuel line sliding onto the nipple on the filter. Others screw into the float chamber and a steel fuel line screws into the filter. The Holley 4180 carburetor has a small filter element, sometimes bronze; sometimes paper, which is located behind the float chamber inlet nut. Replacement of these filters is to be performed on a COLD engine only.
- Wait until the engine is cold. Disconnect the negative battery cable.
- Remove the air cleaner assembly.
- Place some absorbent rags under the filter or float chamber inlet nut.
- On those so equipped, remove the hose clamp and slide the rubber hose from the filter, then unscrew the filter from the bowl. Or, hold the filter with one wrench while unscrewing the fuel line from the filter with another, then, unscrew the filter from the bowl. Or, on the 4180, using 2 wrenches, disconnect the fuel line from the fuel inlet nut, then, unscrew the inlet nut and remove the gaskets, filter element and spring from the bowl.
- Coat the threads of the new filter, or the inlet nut, with non-hardening, gasoline-proof sealer, or, use Teflon tape on the threads, and screw it into place by hand. Tighten it snugly with the wrench.
- Connect the hose or fuel line to the new filter or inlet nut. Most replacement filters come with a new hose and clamps. Use them.
- Remove the fuel-soaked rags, wipe up any spilled fuel and start the engine. Check the filter connections for leaks.
See Figure 3
The 8-360 and 8-390 engines, and some 6-300 engines used a fuel pump mounted filter. The filter element is found inside a screw-on housing. To replace the filter, simply unscrew the housing, discard the fuel, filter and gasket and replace them. Don't overtighten the housing as that would distort the gasket.8-5.0L Fuel Injected Engines
See Figure 4
The inline filter is mounted on the left side frame rail about midway back. To replace the filter:
- Remove the fuel tank cap to relieve system pressure and avoid fuel siphoning.
- Remove the reservoir shield by removing the 3 or 4 screws (depends on the truck).
- Using an oil filter type wrench, unscrew the lower reservoir and slide the filter and canister out from the frame rail.
- Emmpty the fuel from the canister and remove the filter and O-ring.
- Install a new cartridge in the canister and position a new O-ring in the groove.
- Carefully position the canister on the reservoir, being careful to avoid dislodging the O-ring, and tighten it by hand. When hand tight, give it another 1 / 6 turn with the oil filter wrench.
The rubber grommet on the cartridge will seat on the housing stud as the O-ring is compressed.Diesel Engines
See Figure 5
The diesel engine uses a one-piece spin-on fuel filter. Do not add fuel to the new fuel filter. Allow the engine to draw fuel through the filter.
- Remove the spin-on filter by unscrewing it counterclockwise with your hands or a strap wrench.
- Clean the filter mounting surface.
- Coat the gasket or the replacement filter with clean diesel fuel. This helps ensure a good seal.
- Tighten the filter by hand until the gasket touches the filter mounting surface.
- Tighten the filter an additional 1 / 2 turn.
After changing the fuel filter, the engine will purge the trapped air as it runs. The engine may run roughly and smoke excessively until the air is cleared from the system.