Doosan D20S-5 Operation & Maintenance Manual page 139

Cooling System Specifications Cooling System Specifications
Coolant Information Coolant Information
NOTE: The following information is generic and NOTE: The following information is generic and
valid for lift trucks. valid for lift trucks.
Engine operating temperatures have increased to Engine operating temperatures have increased to
improve engine efficiency. This means proper improve engine efficiency. This means proper
cooling system maintenance is cooling system maintenance is especially important.
Overheating, overcooling, pitting, cavitation erosion, Overheating, overcooling, pitting,
cracked heads, piston seizures, and plugged cracked heads, piston seizures, and plugged
radiators are classic cooling system failures. In fact, radiators are classic cooling system failures. In fact,
coolant is as important as the quality of fuel and coolant is as important as the quality of fuel and
lubricating oil. lubricating oil.
DOOSAN recommends that the coolant mixture DOOSAN recommends that the coolant mixture
contain 50% commercially available automotive contain 50% commercially available automotive
antifreeze, and 50% water. antifreeze, and 50% water.
The coolant mix with concentration of antifreeze The coolant mix with concentration of antifreeze
smaller than 30% does not provide sufficient smaller than 30% does not provide sufficient
corrosion protection. Concentrations over 60% corrosion protection. Concentrations over 60%
adversely affect freeze protection and heat transfer adversely affect freeze protection and heat transfer
rates. rates.
Never add coolant to an overheated engine, engine Never add coolant to an overheated engine, engine
damage can result. Allow the engine to cool first. damage can result. Allow the engine to cool first.
If the machine is to be stored in, or shipped to, an If the machine is to be stored in, or shipped to, an
area with freezing temperatures, the cooling system area with freezing temperatures, the cooling system
must be protected to the lowest expected outside must be protected to the lowest expected outside
(ambient) temperature. (ambient) temperature.
The engine cooling system is normally protected to The engine cooling system is normally protected to
-28 -28 (-20 (-20
° ° C C ° ° F F
the factory unless special requirements are the factory unless special requirements are defined.
Check the specific gravity of the coolant solution Check the specific gravity of the coolant solution
frequently in cold weather to ensure adequate frequently in cold weather to ensure adequate
protection. protection.
Clean the cooling system if it is contaminated, the Clean the cooling system if it is contaminated, the
engine overheats or foaming is observed in the engine overheats or foaming is observed in the
radiator. radiator.
Old coolant should be drained, the system cleaned Old coolant should be drained, the system cleaned
and new coolant added every 2000 service hours and new coolant added every 2000 service hours
or yearly. or yearly.
Refer to topic, "Cooling System - Clean, Change" in Refer to topic, "Cooling System - Clean, Change" in
Every 2000 Service Hours or Yearly section. Every 2000 Service Hours or Yearly se
especially important.
cavitation erosion,
NOTICE NOTICE
) with antifreeze, when shipped from ) with antifreeze, when shipped from
-136- -136-
Filling at over 20 liters (5 U.S. gallons) per minute Filling at over 20 liters (5 U.S. gallons) per minute
can cause air pockets in the cooling system. can cause air pockets i
After draining and refilling the cooling system, After draining and refilling the cooling system,
operate the engine with the radiator cap removed operate the engine with the radiator cap removed
until until
temperature and the coolant level stabilizes. Add temperature and the coolant level stabilizes. Add
coolant as necessary to fill the system to the proper coolant as necessary to fill the system to
level. level.
Never operate without a thermostat in the cooling Never operate without a thermostat in the cooling
system. Cooling system problems can arise without system. Cooling system problems can arise without
a thermostat. a thermostat.
defined.
ction.
Maintenance Section Maintenance Section
n the cooling system.
the the coolant coolant reaches reaches normal normal operating operating
the proper