Doosan D50S-5 Operation & Maintenance Manual page 141

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 a minimum of 30% antifreeze or equivalent. contain a minimum of 30% antifreeze or equivalent.
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 fir
All All water water
temperature. temperature.
protected with a 3 to 6% concentration of liquid protected with a 3 to 6% concentration of liquid
supplemental supplemental
regardless of the concentration of antifreeze. regardless of the concentration of antifreeze.
Excessive supplemental coolant additive greater Excessive supplemental coolant additive greater
than than the the
concentrations of antifreeze greater than 65% can concentrations of antifreeze greater than 65% can
cause deposits to form and can result in radiator cause deposits to form and can result in radiator
tube blockage, overheating, and/or water pump seal tube blockage, overheating, and/or water pump seal
damage. damage.
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°C(-20°F) with antifreeze, when shipped from the -28°C(-20°F) with antifreeze, when shipped from the
factory unless special requirements are defined. 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 or and new coolant added every 2000 service hours or
yearly. yearly.
Coolant Water Coolant Water
Hard water, or water with high levels of calcium and Hard water, or water with high levels of calcium and
magnesium ions, encourages the formation of magnesium ions, encourages the formation of
insoluble chemical compounds by combining with insoluble chemical compounds by combining with
cooling system additives such as silicates and cooling system additives such as silicates and
phosphates. phosphates.
The tendency of silicates and phosphates to The tendency of silicates and phosphates to
precipitate out-of-solution increases with increasing precipitate out-of-solution increases with increasing
water hardness. Hard water, or water with high water hardness. Hard water, or water with high
levels of calcium and magnesium ions encourages levels of calcium and magnesium ions encourages
the formation of insoluble chemicals, especially after the formation of insoluble chemicals, especially after
a number of heating and cooling cycles. a number of heating and cooling cycles.
NOTICE NOTICE
is is corrosive corrosive at at engine engine
The The cooling cooling system system
coolant coolant additive additive at at
recommended recommended 6%, 6%, together together
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.
st.
operating operating
should should be be
all all times, times,
with with
140 140
Use a greater concentration (above 50%) of Use a greater concentration (above 50%) of
commercially available automotive antifreeze only commercially available automotive antifreeze only
as as needed needed
temperatures. Do not exceed the recommendations, temperatures. Do not exceed the recommendations,
provided with the commercially available automotive provided with the commercially available automotive
antifreezes, antifreezes,
antifreeze to water. antifreeze to water.
Make proper antifreeze additions. Make proper antifreeze additions.
Adding pure antifreeze as a makeup solution for Adding pure antifreeze as a makeup solution for
cooling system top-up is an unacceptable practice. It cooling system top-up is an unacceptable practice. It
increases the concentration of antifreeze in the increases the concentration of antifreeze in the
Maintenance Section Maintenance Section
for for anticipated anticipated outside outside
regarding regarding the the coolant coolant
(ambient) (ambient)
mixture mixture of of