ARMY TM 9-6115-604-12
NAVY NAVFAC P-8-633-12
MAINTENANCE OF COOLING SYSTEM.
Inspect Water Pump. The water pump is located on the right side of the engine (see Figure 3-3). Inspect the
water pump for secure installation, damage, and evidence of leakage.
Maintenance of Radiator. See Figure 3-17. Radiator maintenance includes inspection, cleaning, and testing,
addition or replacement of coolant.
(1) Inspect. Visually Inspect core assembly for leaks or damage. Using strong light, examine core by looking
through radiator shutter assembly from outside the set and by looking through fan guard assembly from
inside the set. Refer to the next higher level of maintenance for repair.
(2) Service. Service the radiator and cooling system annually by cleaning and flushing the radiator assembly
and the engine cooling manifold.
The radiator gets very hot during operation. Do not remove cap until radiator has
reached a point at which there is no built-up steam pressure.
(a) See Figure 1-1. Remove plug from coolant drain pipe, on the exterior skid base, lower left front of the
(b) Open the radiator fill cap access door on top of the roof and remove the radiator cap.
(c) Open the radiator drain valve located on the skid base Immediately below the exterior radiator shutter
assembly (see Figure 1-1). Allow all used coolant to drain from the radiator into a suitable container and
reclose the drain valve (see Figure 1-1) and reinstall drain plug.
(d) Flush the radiator and engine block before replacing the coolant supply.
(3) Coolant Replacement.
(a) Open the radiator access door on top of the housing and remove the radiator cap.
(b) Fill the radiator with coolant prescribed in Table 3-1, treated with DCA additive, until coolant level is
stabilized at 2 inches (50 mm) below the filler neck or at center of the coolant sight glass assembly (45,
Figure 3-17). This level may decrease due to air displacement once the engine Is operated. Add more
coolant as required until level Is fully stabilized. Refer to Table 3-1 for coolant antifreeze (If needed) and
DCA (corrosion inhibitor) requirements. Refer to Table 3-4 for freezing points, composition, and specific
quantities of antifreeze.
(c) Fasten tag near radiator cap Indicating date of coolant replacement, type of coolant, and level of
protection. Replace radiator cap and close radiator fill cap access door.
(4) Coolant Addition. Check coolant level on coolant sight glass assembly (45, Figure 3-17) daily to determine
whether additional coolant is required. Level should be at center of the sight Also, depending on results of
the DCA coolant test Immediately following, drain part of existing coolant and add make-up coolant as
required. If additional coolant Is required, follow replacement procedures outlined In step (3), above.
(5) DCA Coolant Test.
Engine coolant should be tested every 6 months to ensure that the frequency of water filter servicing or
concentration of corrosion Inhibitor (DCA) is adequate to control corrosion for any operational condition.
The concentration of effective corrosion Inhibitor dissolved In the coolant may be tested, using the Fleet
guard DCA coolant Test Kit or Cummins Coolant Test Kit.