Doosan DX700LC Operation And Maintenance Manual page 268

Heavy duty diesel engines require a balanced mixture of water
and antifreeze. Drain and replace the mixture every year or
2,000 hours of operation, which ever comes first. This will
eliminate buildup of harmful chemicals.
Antifreeze is essential in any climate. It broadens the operating
temperature range by lowering the coolant's freezing point and
by raising its boiling point. Do not use more than 50% antifreeze
in the mixture unless additional freeze protection is required.
Never use more than 68% antifreeze under any condition.
Measuring the Concentration of Coolant
The coolant and its additives can be checked by using coolant
test strips (No: 60.99901-0038). Use the following procedure to
conduct the test:
1. With a coolant temperature of 10° - 55°C (50° - 131°F),
drain 1 liter (1 U.S. quart) it from the radiator into a clean
plastic container.
NOTE:
Do not take the sample from the coolant
recovery
concentration can differ from the concentration
level of coolant in the radiator.
2. Dip test strip, into coolant sample for 3 - 5 seconds.
Remove strip and excessive coolant by giving the strip one
shack.
3. Wait for 45 seconds, for the test strip to change color.
NOTE:
Measuring time should not be more than 75
seconds. If it is over this time limit, the color will
be changed and an inaccurate reading will
result.
4. Compare the color of the test strip with the color table on
the outside of test strip container bottle, and determine
what numeric value corresponds to the color in the table.
A. Check antifreeze concentration levels by comparing
the color change at the end of test paper, with the
green spectrum range, with the green symbol on the
upper portion of the container bottle.
NOTE:
A suitable concentration indicator should
be between 33% and 50%).
B. Check the anticorrosive additives, by comparing
brown color in the middle range of the test strip and
pink color on the lower part of the test strip, with the
brown and pink spectrum range. Where the brown
(vertical) color and pink (horizontal) color intersects
represents the anticorrosive additive level.
NOTE: A reading between 0.3 and 0.8, represents
an adequate additive level.
5. Correct the antifreeze concentration and additive levels.
Inspection, Maintenance and Adjustment
4-80
tank. Recovery tank coolant
OP001123