Doosan 7/26E, Operation And Maintenance Manual

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66 FUEL, LUBRICANTS, AND COOLANT
7/26E, 7/31E, 7/41
LUBRICANT.
The quality of engine oil can affect engine performance, startability and
engine life.
Use of unsuitable engine oil will result in piston ring, piston and cylinder
seizure and accelerate surface wear causing increased oil
consumption, lowered output and, finally engine failure. To avoid this,
use the specified engine oil.
1) Engine Oil Selection
PRO-TEC
2) Oil Viscosity
Engine oil viscosity affects engine startability, performance, oil
consumption, wear and the potential for seizure, etc. Always ensure
that lubricants with the correct viscosity for the operating temperature
are used. Refer to fig 12.
Fig. 12
A. (Single - grade)
B. Ambient Temperature
C. (Multi - grade)
COOLANT
All Doosan portable compressor engines are factory filled with a 50/50
Ethylene glycol base antifreeze/water mix. which provides protection to
-33°C (-27°F)
NOTE
Using a mixture of different brands or quality of oils will adversely af-
fect the original oil quality; therefore, never mix different brand or dif-
ferent type oils.
Do not use API, CA, CB grade and reconstituted engine oil
Engine damage due to improper maintenance, or using oil of the im-
proper quality and/or viscosity, is not covered by the warranty.
IMPORTANT:
• Be sure to add Long Life Coolant Antifreeze (LLC) to soft water.
In cold season, the LLC is especially important. Without LLC, cooling
performance will decrease due to scale and rust in the cooling water
line. Without LLC, cooling water will freeze and expand to break the
cooling line
• Be sure to use the mixing ratios specified by the LLC manufac-
turer for your temperature range.
• Do not mix different types (brand) of LLC, chemical reactions
may make the LLC useless and engine trouble could result
• Replace the cooling water every once a year
CAUTION: When handling Long Life Coolant Antifreeze, wear
protective rubber gloves not to contact with it. If contact with the eyes
or skin should occur, wash with clean water