Kohler LH630-775 Service Manual page 83

Section 7
Cooling System
DO NOT use antifreeze with stop-leak additive(s), or
put any other additives in the cooling system.
Cooling System Maintenance and Service
Maintenance
Maintaining the correct coolant level, cleaning any
debris accumulation from the radiator surfaces, and
insuring all parts are in proper operating condition, is
critical to ensuring long life, proper system
performance and preventing overheating. To ensure
proper air circulation, make sure the radiator, cooling
fan, drive belt, pulleys, cooling fins, and external
surfaces of the engine are kept clean and in good
condition at all times. Check the coolant level and
clean away any debris accumulation daily or before
each use. At the same time inspect the hoses and all
system connections for signs of leakage. Make sure the
cooling fan is not cracked or missing any blades.
Check that the fan belt and the two drive pulleys, are
in good condition and the proper belt tension is
present. See Figure 7-2.
Figure 7-2. Checking Belt Tension.
Servicing
Every 100 hours of operation (more often under
extremely dusty, dirty conditions), clean the
removable screen, cooling fins of the radiator, all
shrouding and external surfaces of the engine as
necessary. Check the condition of fan assembly and v-
belt tension. Do not operate the engine without all
shrouds and protective guards installed.
Lift the screen vertically to remove for cleaning/
servicing. Clean the screen and cooling fins of the
radiator with a soft brush or blow out using clean
compressed air. See Figure 7-3. To avoid damage to the
screen and cooling fins, do not use a high pressure
washer to clean.
7.2
Figure 7-3. Cleaning Radiator and Screen.
Engine coolant should be changed every two years or
1000 hours, whichever comes first. When changing
the engine coolant, the system should also be flushed
to remove any contaminants left behind during
draining. Following are general recommended
procedures for checking, draining, flushing, and filling
the cooling system.
Checking Coolant Level
The coolant level should be checked at the overflow
reservoir, located behind the radiator on the fan
shroud. See Figure 7-4.
Figure 7-4. Overflow Reservoir Location.
1. Check the coolant level within the overflow
reservoir. Coolant level should be between the
"FULL" and "ADD" marks on the reservoir. See
Figure 7-5. Do not operate the engine with the
coolant level below the "ADD" mark.
Add coolant to the overflow reservoir as
required, which is a 50/50 mixture of ethylene
glycol and water (distilled or deionized water is
recommended).