DETROIT DIESEL Engine Systems The radiator is reverse-flushed as follows: 1. Remove the radiator inlet and outlet hoses and replace the radiator cap. 2. Attach a hose at the top of the radiator to lead water away from the engine. 3. Attach a hose to the bottom of the radiator and insert a flushing gun in the hose. SiAL CAM BOLT SPLINE COVER 4. Connect the water hose of the gun to the water outlet and the air hose to the compressed air outlet. 5. Turn on the water and, when the radiator is full, turn on the air in short blasts, allowing the radiator to fill between air blasts. I PUMP WEAR I I HOUSING PLATE IMPELLER GASKET ,799 NOTE: Apply air gradually.
Do not exert more than 30 psi (207 kPa) air pressure. Too great a pressure may rupture a radiator tube. I Fig. 20 - Raw Water Pump Details and Relative Location of Parts 6. Continue flushing until only clean water is expelled from the radiator. When water connection seals and hoses are installed, be sure the connecting parts are properly aligned and the seal or hose is in its proper position before tightening the clamps. All external leaks should be corrected as soon as detected. The cylinder block and cylinder head water passages are reverse-flushed as follows: 1. Remove the thermostat and the water pump.
The fan belt must be checked and adjusted, if necessary, to provide the proper tension and the fan shroud must be tight against the radiator core to prevent re-circulation of air which may lower the cooling efficiency. 2. Attach a hose to the water inlet of the cylinder block to drain the water away from the engine. 3. Attach a hose to the water outlet at the top of the cylinder block and insert the flushing gun in the hose. 4. Turn on the water and, when the water jackets are filled, turn on the air in short blasts, allowing the engine to fill with water between air blasts. Water Pump 5. Continue flushing until the water from the engine runs clean.
The centrifugal type water pump is mounted on the engine front cover and is driven by a front camshaft gear. This pump circulates the engine coolant through the cylinder block, cylinder head, heat exchanger or radiator and the oil cooler. If scale deposits in the radiator cannot be removed by chemical cleaners or reverse-flushing as outlined above, it may be necessary to remove the upper tank and rod out the individual radiator tubes with flat steel rods. Circulate water through the radiator core from the bottom to the top during this operation. The pump consists of a bronze impeller secured to a stainless steel shaft with a lock nut.
A gear is pressed on the opposite end of the shaft and the shaft turns on two ball bearings. An oil seal is used ahead of the front bearing and a spring-loaded face type water seal is used in back of the impeller. The pump ball bearings are lubricated with oil splashed by the water pump gear. Miscellaneous Cooling System Checks In addition to the above cleaning procedures, the other components of the cooling system should be checked periodically to keep the engine operating at peak efficiency. The cooling system hoses, thermostats and radiator pressure cap should be checked and replaced if found to be defective.
Contact an authorized Detroit Diesel Allison Service Outlet if more information is needed. Page 29