Q: How to replace the fuel filter on a Mercury Grand Marquis?
A: On 1996 and earlier models, the fuel filter is located under the vehicle on the inside of the left frame rail. On 1997 and later models, it is located under the vehicle on the inside of the right frame rail. Inspect the hose fittings at both ends of the filter to see if they're clean. If there is more than a light coating of dust present, clean the fittings before proceeding. Relieve the fuel system pressure. Removal of the hairpin clip from each fitting is a two-stage procedure. First, spread the two clip legs apart about 1/8-inch to disengage them, then push in on them. Pull on the other end of the clip to detach it from the fitting. Use a small screwdriver to pry the fuel fitter line clip off. Once both hairpin clips are released, grasp the fuel hoses, one at a time, and pull them straight off the filter. Be prepared for fuel spillage. After the hoses have been detached, check the clips for damage and distortion. If they were damaged in any way during removal, new ones must be used when the hoses are reattached to the new filter. If new clips are packaged with the filter, be sure to use them in place of the originals. Remove the bolts and detach the filter and bracket assembly. On 1988 through 1994 models, note which way the arrow is pointing - the new filter must be installed the same way. Use a screwdriver to loosen the clamp and remove the filter from the bracket. On 1995 and later models, the filter and bracket are a one-piece unit and cannot be separated. Install the new filter with the arrow pointing in the right direction and tighten the clamp. On all models, install the filter/bracket assembly and tighten the bolts securely. Carefully push each hose onto the filter until it's seated against the collar on the fitting, then install the hairpin clips. Make sure the clips are securely attached to the hose fittings - if they come off, the hoses could back off the filter and a fire could result! Start the engine and check for fuel leaks.