Fuel Filter Location 1988 Mercury Grand Marquis, 5.0, U.S.

1988 Mercury Grand Marquis

Fuel Filter Location

I’m trying to replace my fuel filter and I can’t find it. I have looked along the frame on the driver side where the fuel line is, but there is nothing there. Did they make some models with the filter in the tank???

The inline filter is mounted on the same bracket as the fuel supply pump. It is on the frame rail under passenger side of the vehicle, in front of the fuel tank.

Fuel Filter Replacement

The fuel filter is of a one-piece construction which cannot be cleaned. If it becomes clogged, it must be removed and replaced. When replacing the fuel filter use the filter specified for the engine being serviced.

The inline filter is mounted on the same bracket as the fuel supply pump. It is on the frame rail under passenger side of the vehicle, in front of the fuel tank. To replace the filter:
Fig. 4: Whenever you see a warning label, read it
fuel pump location

Fuel supply lines on fuel injected vehicles will remain pressurized for some time after the engine is shut off. Fuel pressure must be relieved before servicing the fuel system.

To Remove:

1.Disconnect the negative battery cable.
2.Relieve the fuel system pressure as follows: A.Remove the fuel tank cap to relieve any pressure in the fuel tank.
B.Remove the cap from the Schrader valve located on the fuel injection supply manifold in the engine compartment.
C.Attach fuel pressure gauge T80L–9974–A or equivalent, to the Schrader valve and drain the fuel through the drain tube into a suitable container.
D.After the fuel system pressure is relieved, remove the fuel pressure gauge and install the cap on the Schrader valve.

3.Raise and safely support the vehicle on jackstands.
4.Disconnect the fittings from both ends of the fuel filter as follows: A.Inspect the visible portion of the fitting for dirt accumulation. If more than a light coating of dust is present, clean the fitting before disassembly.
B.Some adhesion between the seals in the fitting and the filter will occur with time. To separate, twist the fitting on the filter, then push and pull the fitting until it moves freely on the filter.
C.Remove the hairpin clip from the fitting by first bending and breaking the shipping tab. Next, spread the 2 clip legs by hand about 1 ⁄ 8 in. (3.1mm) each to disengage the body, then push the legs into the fitting. Lightly pull the triangular end of the clip and work it clear of the filter and fitting.


Do not use hand tools to complete this operation. Damage to the fittings may result.

D.Grasp the fitting and pull in an axial direction to remove the fitting from the filter. Be careful on 90°elbow connectors, as excessive side loading could break the connector body.
E.After disassembly, inspect the inside of the fitting for any internal parts such as O-rings and/or spacers that may have been dislodged from the fitting. Replace any damaged connector(s).

Fig. 5: Carefully remove the hairpin clip
fuel filter clip
Fig. 6: With a rag under the hose to catch any gasoline spillage, slowly separate the line from the filter
fuel filter hose

Filter retainer bolts

5.If equipped, remove the filter retainer bolts and remove the filter and retainer from the mounting bracket. Remove the filter from the retainer. Note that the direction of the flow arrow on the fuel filter. Remove the rubber insulator rings, if installed. Inspect the rings for cracks or wear, and replace if needed.

Fig. 7: Remove the hardware securing the filter to the housing
fuel filter hardware
Fig. 8: Lower the filter assembly, then separate the pieces
fuel filter

To install:

6.Install the fuel filter with the flow arrow facing the proper direction as before, then tighten the filter retaining clamp(s).
7.If the original filter was equipped with rubber insulator rings, install the rubber insulator rings on the new filter. Install the filter into the retainer with the flow arrow pointing in the correct direction. Install the retainer on the bracket and tighten the mounting bolts to 27–44 inch lbs. (3–5 Nm).
8.Connect the fittings at both ends of the fuel filter as follows: A.Install a new connector if damage was found. Insert a new clip into any 2 adjacent openings with the triangular portion pointing away from the fitting opening. Install the clip until the legs of the clip are locked on the outside of the body. Piloting with an index finger is necessary.

Wipe the filter end

B.Before installing the fitting on the filter, wipe the filter end with a clean cloth. Inspect the inside of the fitting to make sure it is free of dirt and/or obstructions.
C.Apply a light coating of engine oil to the filter end. Align the fitting and filter axially and push the fitting onto the filter end. When the fitting is engaged, a definite click will be heard. Pull on the fitting to make sure it is fully engaged.

9.Connect the negative battery cable. Start the engine and check for fuel leaks.
10.Lower the vehicle.