How to Change the External Fuel Pump on a 1988 Ford F-250

Iskandar Blogger 12:40 AM

With an engine produced by International, the 7.2-liter 175-horsepower diesel engine in a 1988 Ford F-250 used an external fuel pump. This engine typically lasts in excess of 300,000 miles before overhaul, when maintained regularly. Diesels absorb moisture in the fuel tank that settles to the bottom of the tank. A water separator extracts the water from the fuel. Because water is non-compressible, it cannot enter the cylinder or it will result in a bent rod. The fuel pump is mechanical and mounted on the passenger side of the timing chain. An eccentric on the camshaft drives the fuel pump.

Instructions

    1

    Loosen the three fuel line fittings on the fuel pump using a line wrench. This procedure is to break the lines loose because they get much tighter over time or through corrosion. Loosen the lines with the mounting bolts tight, so the lines do not bend. Tighten the lines down snug, so they will be easily removable when needed. Snug these lines to keep the fuel pump from cocking because of cam pressure when removing the main bolts. Once the camshaft is on the low side to avoid exerting pressure on the pump, remove the main mounting bolts.

    2

    Loosen the two bolts securing the fuel pump to the block. Do not remove them at this point. Wiggle the pump by hand to see if it has pressure on the bolts. The cam eccentric must be on the low side to remove the pump or the eccentric will be applying pressure to the pump arm making extraction and insertion extremely difficult. Bump the engine over a small amount and check the pump until the cam is on the low side and the pump is free of pressure.

    3

    Continue to remove the two securing bolts and the pump. Scrape all remaining gasket material from the block-mounting surface.

    4

    Insert the two bolts through the pump and add the gasket over the bolts. Insert the pump into the block and start the bolts by hand to prevent stripping the threads. Tighten the bolts on the pump to 30 foot-pounds with the socket.

    5

    Install the fuel line fittings by hand to prevent stripping; tighten them with the line wrench. Start the engine and check for leaks.