Technical data
OPERATION&MAINTENANCE MANUAL 
9、cooling system 
Fig12 Cooling system 
1 radiator 2 heat retainer 3 fan 4 water 
pump 5 inlet pipe 
The cooling system is of forcible circulating water-cooled type, see figure 12 for 
detail. The cooling system contains radiator, water pump, fan, heat retainer, air guide 
cover and etc.(diesel    engine without air guide cover and radiator)   
Cooling liquid in the radiator is delivered to water channel by water pump, and then 
enters into the surrounding of the cylinder sleeve and last flows into cylinder header by 
the cylinder sleeve. The used cooling liquid returns to the radiator through heat retainer 
at the front of the cylinder head and the outlet pipe. The heat retainer closes when the   
temperature of the water flowing out is less than 70°C, and the cooling liquid flows into 
inlet pipe of the water pump through a small circulation    on front plate of the cylinder, 
then it flowed into the water pump a second time to realize a small circulation; when the 
water flowing out is 70°C~80°C,the heat retainer opens, and the cooling liquid flows into 
the header tank of the radiator through    the heat retainer, and flows into the lower tank 
through a flat copper pipe. During the process, the cooling liquid is cooled by the drafting 
or exhausted by the fan. Up to now, a big circulation is completed. Air drafting or 
exhausting is adopted for the fan as required.     
Water pump is a centrifugal type. The water pump is driven by fan belt surround the 
shaft belt pulley. During use, if the water backfill is damaged, which leads to serious 
water leakage in the lower part of the water pump, please change a new one. Do not 
clock the water backfill if it is damaged, otherwise, it may enter into the bearing and 
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