Michael Johnson
Associate Editor, 5.0 Mustangs & Super Fords
June 1, 1999

Step By Step

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Here’s what you’ll need when replacing your water pump. Obviously, the star of the show is the Edelbrock water pump, however, other items such as new radiator hoses, thermostat and gasket, and radiator flush are also needed to complete the installation. Our radiator hoses probably didn’t need replacing, but a previous owner had wrapped the upper hose in braided line and that stuff just had to go. Also, with 83,000 miles on the car, we thought it would be a good idea to replace them.
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Start by draining the radiator. Then remove the fan and fan shroud. There are four bolts holding the fan and two bolts at the top of the shroud. The fan and shroud will then come out together. The factory Ford tool holder (the radiator) can stay in place.
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With the fan and shroud out of the way, access to the water pump is much improved. However, there are a few other components we must remove before we get to the water pump.
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Remove the serpentine belt and water pump pulley. The next thing to remove is the accessory bracket that attaches to the water pump, A/C compressor and power steering pump.
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Loosen the remaining bolts to the water pump and remove it.
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This vent hole tells the story of a water pump gone bad. The hole serves as a vent for the water pump shaft. The vent hole releases hot air that builds up inside the shaft. Eventually, the seals at each end of the shaft fail, causing water to get into the shaft area and come out of the vent hole, thereby necessitating the water pump’s replacement.
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With the water pump removed, the leftover gasket material must be completely removed before you install the new water pump. Start this process with a scraper.
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After the scraper, use a drill with a Scotch pad to remove any excess gasket material.
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We then removed the thermostat housing, repeating the same gasket-removing process as with the water pump.
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Edelbrock also includes these brass water fittings with the water pump. The threads must be treated to thread sealant before installation or you will have leaks when the job is done. After prepping the fittings, install them carefully using a wrench.
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Use weatherstrip adhesive to hold the gasket in place during installation.
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Once the adhesive is applied, place the gasket on the water pump in the proper location. Allow a few minutes for the adhesive to set up.
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Do the adhesive thing with the thermostat housing in this manner, and install it with the new 180-degree thermostat and gasket.
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With the adhesive set up, we can go ahead and install the Edelbrock water pump.
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With the water pump installed, we can now install the hoses. Our auto parts store didn’t have the water-pump-to-heater-core-inlet hose, so we had to reuse the old one. This hose goes from the water pump to the metal tube that travels to the heater core. Always use new hose clamps.
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Reassemble everything in reverse order. As you can see here, we have one bolt in the water pump pulley to make it easier to reinstall the fan and shroud. By attaching one bolt in the pulley, we can reinstall the serpentine belt. This way the serpentine belt will hold the pulley in place while we’re reinstalling the fan. Also, if your fan clutch is dirty (and it probably is) use carburetor cleaner to clean it. A clean fan clutch is a properly functioning fan clutch.
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Reinstall the fan and shroud. Fill the radiator with water and make sure there are no leaks. With the radiator cap off and the radiator full of water, start the car and wait for everything to come up to temperature. You’ll be able to tell when the thermostat opens because water will start flowing out of the radiator and then the water level will begin to drop. Top off the water level and put the radiator cap on. At this time, you can flush the cooling system using a can of radiator flush. With our Edelbrock water pump, along with our 180-degree thermostat, our coolant temperature has not gone above the second mark on the gauge. Now that’s cool.

It happens to every water-cooled car. We have to swap out our water pump. In our case, we're replacing our factory unit with an Edelbrock Victor-series aluminum water pump. The water pump (available in both unpolished, PN 8840, and polished, PN 8845) is heavy-duty for both street and racing applications. Externally, the Edelbrock pump is exactly the same as the stocker to provide compatibility with all accessories and pulleys. The 8840s and 8845s are reverse-rotation pumps for ’86-’93 5.0 V-8s, and offer increased durability and cooling potential.

After 83,000 miles of use, my factory pump decided it was done taking my abuse and was ready to take its place in the aluminum graveyard in the sky. We first noticed the problem while leaning on the radiator support one day pondering the next performance addition. We saw a subtle, yet attention-grabbing, leak coming from the center of the engine on the underside. That’s the one good thing about a water pump that goes out—it’s easy to diagnose. If this happens to your car’s water pump, you’ll need to allocate about 3-4 hours from start to finish for the job. Along with our Edelbrock water pump, we also visited our local auto parts store for new radiator hoses, coolant, clamps, thermostat and gasket, a can of radiator flush, and a tube of thread sealant.