Doosan AD158TI, Operation & Maintenance Manual

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General information - 31 -
4.3. Cooling System
4.3.1. Coolant level check and refill
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Replenish the deficient coolant in the expansion tank every day before running. The coolant must be
changed at intervals of 1,200 hours operation or six months whichever comes first. If the coolant is being
fouled greatly, it will lead engine overheat or coolant blow off from the expansion tank.
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The clean fresh water should be used for engine coolant.
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Additional agent (35 ~ 40% anti-freeze and 3 ~ 5% anti-corrosion agent) should be mixed with fresh water
for engine coolant to prevent the cooling system problem like freezing, corrosion and etc.
Caution :
Suitable mixture of anti-freeze and anti-corrosion agent can protect the engine corrosion from
deteriorating and raises a boiling point, but by using unsuitable mixture engine components like
water pump impeller and water jacket of cylinder block may be occurred a malfunction by any bad
corrosion damage or cavitation.
(1) Coolant replenishment
Let the plug in the highest level of the water lines or the upper plug of wet turbocharger open,
and fill the coolant about three forth of the expansion tank slowly until the air bubbles in water do
not come out through the plug hole. Then reassemble the plug.
After filling the coolant, run the engine at the idle rpm for around 5 minutes and you will find out
the engine coolant level becomes lower than before cause of escaping the air bubbles in water.
Then stop the engine and replenish additional coolant properly.
(2) Coolant change
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Open the pressure cap of expansion to remove the air pressure.
Caution :
When remove the pressure of the filler cap while the engine is still hot, cover the cap
with a cloth, then turn it counter-clockwise slowly to release internal steam pressure.
This will prevent a person from scalding by hot steam spouted out from the filler cap.
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V-type engines have 5 places of drain plug as follows
1) Lower part of right exhaust elbow
2) Front part of the left exhaust manifold cover
3) Lower part of the heat exchanger outlet pipe
4) Lower part of oil cooler
5) Cylinder block part of starter upper side.
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After water draining, re-assemble the drain plugs and then replenish the coolant as same as
″ (1) Coolant replenishment ″ .