Cleaning The Cooling Circuit; Inter Cooler - Doosan DP158L Series Operation & Maintenance Manual

5. After checking the coolant level when the engine is
warmed up, replenish coolant if necessary.
DANGER
If the engine is hot, wrap the coolant pressure cap with
a cloth upon opening it so that the steam may be
discharged. This can prevent you from burning by the
hot steam coming out of the cap inlet.
CAUTION
• Do not mix antifreezes from different manufac-
turers.
• Do not mix the coolant with different concentra-
tions.
• Do not add antirust which is not recommended by
us.
• As insufficient coolant concentration may cause
corrosion or freezing, on the other hand, an exces-
sive concentration may degrade the cooling perfor-
mance. Mix coolant with 40% antifreeze and 3~5%
additives (DCA4) to prevent corrosion.
WARNING
Discard exchanged coolant according to the regula-
tions set forth by the relevant authorities. Disposing of
exchanged coolant into the ground, sewers, drains,
rivers, or the sea will cause serious environmental
pollution. Violation of regulations regarding discard of
coolant without observing the handling regulations,
will be punished.

Cleaning the cooling circuit

If the internal coolant circuit is contaminated by corrosion or
foreign substance, the cooling effect is reduced. The resis-
tance in the coolant circuit may damage the mechanical seal
of the coolant pump.
The negative impact on the cooling circuit may be caused by
use of improper antifreeze or corrosion inhibitor, or by use of
coolant without such ingredients. If the coolant pump leaks or
the coolant is severely contaminated within short period of
time (6 months) after start of using the operation (e.g., the
coolant color becomes muddy - probably brown, gray or
black depending on the degree of contamination), before
removing the coolant pump, clean the cooling system in the
following way.
1. Discharge the coolant.
2. If you want to clean the cooling circuit swiftly, remove the
thermostat.
3. Mix water and 1.5% of cleaning solution and fill the
cooling circuit with this liquid.
4. Load the engine. When the coolant temperature reaches
60°C, run the engine for about 15 minutes.
5. Discharge the cleansing solution.
6. Repeat the step 3 and 4 above.
7. Fill the cooling circuit with hot water.
8. While running the engine at idle speed for 30 minutes,
check if there is any leakage in the drain plug and coolant
line. If the coolant is insufficient, replenish it.
Clean the cooling circuit regularly with cleansing solu-
tion.

Inter cooler

The air cooler adopts an air cooling fan, which has sufficient
cooling capacity. The life and performance of an air cooler
greatly depends on the intake air conditions. Dirty air may
contaminate and clog the cooling pins. This results in
reduced engine power or engine failure. So, always check
the intake system for air leak, damage or contamination of air
filter.
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4. Regular inspection
CAUTION