Kohler Optimize Your Generator's Cooling System: Essential Tips for Low Coolant Levels

4.6.2Cooling System Inspection

To prevent generator shutdown or damage because of overheating:

DKeep the cooling air inlets clean and unobstructed

DInspect the radiator’s exterior for obstructions and remove dirt and foreign material with a soft brush or cloth to avoid damaging the radiator fins.

D Check the hoses and connections for leaks and replace any cracked, frayed, or spongy hoses.

DCheck the condition and tension of the radiator water pump belt(s).

DCheck the rubber seal of the radiator’s pressure cap and replace a cracked or deteriorated cap. Remove dirt and other debris from the pressure cap and filler neck. The pressure cap raises the boiling point of the coolant, enabling higher operating temperatures. If the cap leaks, replace it with the same rating type of cap. Find the pressure cap rating in Figure 4-5.

Item	Rating
Pressure cap	97 kPa (14 psi)

Figure 4-5Pressure Cap Rating

4.6.3Draining Cooling System

The radiator contains a coolant drain valve to drain the cooling system. When draining the coolant, remove the radiator’s pressure cap, which will allow the entire system to drain and will prevent air pockets from forming and restricting coolant passage to the block.

1.De--energize the block heater, if equipped.

2.Remove the pressure cap to allow the entire system to drain and prevent air pockets from restricting coolant flow through the engine block.

3.Open the coolant drain valve and allow the system to drain.

4.If the inside of the radiator has mineral deposits or the used coolant contains dirt or grease, go to Section 4.6.4, Flushing and Cleaning. If the cooling system does not have mineral deposits, refill the cooling system as instructed in Section 4.6.5, Filling Cooling System.

4.6.4Flushing and Cleaning

For optimum protection, drain, flush, and refill the cooling system at the interval listed in the service schedule.

Flushing and Cleaning Procedure

1.Flush the system with clean water.

2.Drain, clean, and flush the coolant overflow bottle.

3.Refill the cooling system as instructed in Section 4.6.5.

4.6.5Filling Cooling System

	Coolant Capacity, L (qt.)
Model	Generator Set	With Block Heater
38RCL	15.5 (16.4)	17.0 (18.0)
48RCL	17.5 (18.5)	19.0 (20.1)
60RCL	17.5 (18.5)	19.0 (20.1)

Figure 4-6Coolant Capacity

Note: Do not add coolant to a hot engine. Adding coolant to a hot engine can cause the cylinder block or cylinder head to crack. Wait until engine has cooled.

1.Close the radiator’s coolant drain valve and tighten the hose clamps.

2.Fill the radiator with the recommended coolant mixture of 50% ethylene glycol and 50% clean, softened water to inhibit rust/corrosion and prevent freezing. The coolant capacity is shown in Figure 4-6.

3.Operate the engine with the radiator cap removed until the thermostat opens and the upper radiator hose becomes hot.

4.Stop the engine and allow it to cool.

5.Add coolant to the radiator to just below the overflow tube on the filler neck. See Section 1, Service Views, for the overflow tube location.

6.Replace the radiator’s pressure cap.

7.Maintain the coolant level in the coolant overflow bottle between the High and Low markings. See Section 1, Service Views, for the coolant overflow bottle location.

8.Re--energize the block heater, if equipped.

52 Section 4 Scheduled Maintenance TP-6810 11/13