An often-overlooked area of maintenance on 1980-1996 Ford F-150 trucks is the cowl drain. Prior to 1997, most of these trucks used a series of elongated louvers on the cowl, which can become clogged with leaves, dirt and debris. If left unchecked, the accumulated debris can interfere with the proper drainage of the cowl, trapping moisture and causing corrosion. This can result in a number of problems, including heater core or computer damage.

It is recommended that the following procedure be performed at least once every 5 years or as needed.

	Remove the small body screws from the plastic fender liner
	Side screws . . .
	. . .and top screws --Once the screws are removed, the panel can be pulled down far enough to access the cowl drain(s). A small pair of locking pliers may be used with a wire or bungee cord to hold the panel out of the way.
	This is the rubber drain grommet. It is held in place by a pair of plastic retaining plugs
	Using a pry tool or screwdriver, carefully pry out the plastic grommet retaining plugs
	Remove the grommet completely (clean thoroughly before reassembly)
	Thoroughly clean out the debris from inside the cowl chamber. Allow chamber to dry completely and coat with a rubberized undercoating, if desired. Assembly is the reverse of disassembly.

Thank you, dustybumpers!
ALL IMAGES COURTESY OF DUSTY BUMPERS, Original topic here.​