7.3L Power Stroke Cooling System Upgrades

Diesel Power 1997 Ford F350 Cooling System Components

Bosch's water pump for the 7.3L Power Stroke is brand-new (PN 99170) and came with all the necessary gaskets, O-rings, and even a new water neck outlet. It can be had for just $140.95 from Auto Anything. In addition, we opted to use DieselSite's 203-degree thermostat during the install, and it also supplied us with an OE water neck inlet and one of its coolant filtration systems.

Bosch's water pump for the 7.3L Power Stroke is brand-new (PN 99170) and came with all the

The latest installment of our '97 Ford F-350 project entailed tackling another preventative maintenance issue: replacing the factory, 145,000-mile water pump. It's anyone's guess how long a 7.3L's stock water pump will last, as we've seen some fail with little more than 100,000 miles on them, and some that have lasted beyond 200,000 miles. More often than not, a damaged coolant system leads to this vital component failing. Things like cooling system contamination, bearing overload, an unbalanced fan clutch, insufficient clearance between the fan and fan shroud (or radiator), and engine overheating can all contribute to a failed water pump. Being proactive, we decided to replace our 7.3L Power Stroke's factory unit with a brand-new water pump from Bosch. This is a weekend project anyone can handle and only required a few special tools to get the job done.

Diesel Power 1997 Ford F350 Cooling System Coolant Drain

We got started by draining all of our Power Stroke's coolant into a 5-gallon bucket and an empty cooler. Then we removed every radiator hose, the four bolts securing the water pump pulley were loosened using a 10mm socket, and the serpentine belt was pulled.

We got started by draining all of our Power Stroke's coolant into a 5-gallon bucket and an

For added performance and insurance, we also installed a 203-degree thermostat and coolant filtration system from DieselSite. With the truck now running at its ideal operating temperature and the engine benefiting from uncontaminated coolant, our water pump's life will be prolonged considerably, and our cooling system should be problem free for years to come.

Diesel Power 1997 Ford F350 Cooling System Failed Pump

Why Water Pumps Fail:
The photo shown below is of an '01 7.3L Power Stroke engine's failed water pump with just 127,000 miles on it. Notice the odd angle of the pulley? This is because the bearing assembly in the water pump failed. Typically, the seal will fail first, in which you'll notice a slight coolant leak, or drip. Obviously, this was not the case here, and there were no warning signs that the pump was on its way out. The truck owner was lucky the failed bearing assembly didn't damage the front engine cover, fan clutch, or even the radiator. The seven main causes of water pump failure are:
Cooling system contamination
Overheated cooling system
Bearing overload
Excessive fan belt tension
Insufficient clearance between the fan and shroud, or radiator
Unbalanced fan clutch
Excessive vibration due to loose (or broken) motor mounts

The fan clutch was removed from the water pump pulley using a fan clutch wrench set from Ford (the only specialty tool needed to do the job), and the fan clutch and fan shroud were removed. We made sure to leave the fan clutch standing straight up and down once it was out of the truck to keep it in phase with the engine.
The fan clutch was removed from the water pump pulley using a fan clutch wrench set from F
Next, the water pump pulley was removed, followed by the radiator hose on the pump inlet, the heater hose, and all water pump housing bolts using a 10mm socket (shown).
Next, the water pump pulley was removed, followed by the radiator hose on the pump inlet,
With the factory water pump removed, we inspected our upper and lower radiator hoses. With signs of age, wear, and corrosion present, we opted to replace them with these hoses from O'Reilly Auto Parts (upper PN 22216, lower PN 22158).
With the factory water pump removed, we inspected our upper and lower radiator hoses. With

After that, we pulled the plug below the thermostat housing area and replaced it with a barbed fitting supplied by DieselSite (arrow). This brass fitting allows the water pump to route coolant up to the supplied filter included in its coolant filtration system. Then the supplied water inlet O-ring and water inlet neck were installed, followed by the water pump housing gasket with a light coat of multipurpose grease.
After that, we pulled the plug below the thermostat housing area and replaced it with a ba
According to DieselSite, 7.3L engines were designed to run at 203 degrees. On '941/2 and '95 7.3L Power Strokes, a 203-degree thermostat from International was used, but the thermostat shaft was too short in length to shut off the internal water pump bypass, causing inconsistent coolant flow in the system. The factory '96 to '03 7.3L thermostats are the correct length but are only 195-degree units (which begin opening around 170 degrees). DieselSite's 203-degree unit starts opening at 185 degrees, which keeps the engine much closer to its ideal operating temperature for optimal engine efficiency. DieselSite is the only manufacturer of this 203-degree thermostat.
According to DieselSite, 7.3L engines were designed to run at 203 degrees. On '941/2 and '
Then we cleaned up the mounting surface on the engine's front cover, installed the supplied water outlet neck on the water pump, swapped the heater hose outlet and the coolant temperature sensor from our factory water pump onto the new Bosch unit (arrows), and installed the water pump.
Then we cleaned up the mounting surface on the engine's front cover, installed the supplie

DieselSite's coolant filtration system was a breeze to install. It routes coolant up to this billet filter housing (which we mounted along the driver side of the firewall), through a Baldwin spin-on filter (removing all contaminants in the system), and then to the coolant overflow reservoir. The kit works as a bypass-style system, in which a small amount of coolant is filtered on each pass and loose particles within the cooling system can be taken out of the equation. This extends the life of the water pump, water neck, radiator, radiator hoses, and sells for just $99.
DieselSite's coolant filtration system was a breeze to install. It routes coolant up to th
Once the coolant filtration system was buttoned up, we installed our lower radiator hoses, reinstalled the water pump pulley and serpentine belt, and torqued the water pump pulley bolts with a 10mm socket. After that, the fan clutch, fan shroud, and upper radiator hoses were reinstalled. Last but not least, we filled the cooling system with approximately 5 gallons (20 quarts) of Caterpillar's Extended Life coolant, installed the radiator cap, and ran the engine up to its normal operating temperature. Then we checked for leaks and concluded by topping off our overflow reservoir (22 quarts were needed in all).
Once the coolant filtration system was buttoned up, we installed our lower radiator hoses,

SOURCES
Auto Anything 9210 Sky Park Court Suite 100 San Diego CA 92123 800-874-8888 www.autoanything.com	Caterpillar 100 North East Adams Street Peoria IL 61629 309-675-1000 www.cat.com
DieselSite P.O. Box 2079 Crystal River FL 34429 888-414-3454 www.dieselsite.com	O'Reilly Auto Parts 233 South Patterson Avenue Springfield MO 65802 800-755-6759 www.oreillyauto.com
Bosch Auto Parts 38000 Hills Tech Court Farmington Hills MI 48331 888-715-3610 www.boschautoparts.com