Thermo King 002008, Manual

Page: 57 / 155

Engine Maintenance
57
Checking the Antifreeze
Check the solution concentration by using a
temperature compensated antifreeze hydrometer
or a refractometer (P/N 204-754) designed for
testing antifreeze. Maintain a minimum of
50 percent permanent type antifreeze concentrate
and 50 percent water solution to provide
protection to -30 F (-34 C). Do not mix antifreeze
stronger than 68 percent permanent type coolant
concentrate and 32 percent water for use in
extreme temperatures.
Changing the Antifreeze
1. Run the engine until it is up to its normal
operating temperature. Stop the unit.
2. Open the engine block drain (located behind
the starter) and completely drain the coolant.
Observe the coolant color. If the coolant is
dirty, proceed with a, b, and c. Otherwise go
to 3.
a. Run clear water into the radiator and allow
it to drain out of the block until it is clear.
b. Close the block drain and install a
commercially available radiator and block
flushing agent, and operate the unit in
accordance with instructions of the
flushing agent manufacturer.
c. Open the engine block drain to drain the
water and flushing solution.
3. Run clear water into the radiator, and allow it
to drain out of the block until it is clear.
4. Inspect all hoses for deterioration and hose
clamp tightness. Replace if necessary.
5. Loosen the water pump belt. Check the water
pump bearing for looseness.
6. Inspect the radiator cap. Replace the cap if the
gasket shows any signs of deterioration.
7. If using ELC concentrate, mix one gallon of
ELC concentrate and one gallon of de-ionized
or distilled water in a container to make a
50/50 mixture. (Do not add antifreeze and
then add water to the unit. This procedure may
not give a true 50/50 mixture because the
exact cooling system capacity may not always
be known.)
8. Refill the radiator with the 50/50 antifreeze
mixture and make sure to bleed the air from
the cooling system as needed.
Bleeding Air from the Cooling
System
Jiggle pin thermostats are original equipment on
units that have TK 482/486 engines. Jiggle pin
thermostats make it unnecessary to bleed the air
out of the engine block because they keep air from
being trapped in the engine block. Normally, all
but about 1.5 qt (1.4 liters) of coolant drain out of
the cooling system when it is drained. If
approximately half of the Cooling System
Capacity (see Specifications Chapter) seems to fill
the cooling system after it has been drained, air
has been trapped in the block. Bleed the air out of
the block using the following procedure:
NOTE: If an engine runs with air trapped in the
block, the engine may be damaged. The high
water temperature switch may not protect an
engine that has air trapped in the block, because
the high water temperature switch is designed to
protect an engine from overheating due to
failures in the cooling system.
1. Loosen the plug on the back of the water
pump below the thermostat cover until coolant
comes out of the plug fitting.
2. Tighten the plug.
3. Pour coolant into the system until it appears to
be full.
4. Make sure that the amount of coolant that
goes back into the system is approximately
equal to the amount of coolant that came out
of the system.
CAUTION: Avoid direct contact with hot
coolant.
CAUTION: Avoid direct contact with hot
coolant.
CAUTION: If you suspect that air is
trapped in the block, do not start the
engine without bleeding the air out of the
block.