Hobart 120CU20, Operation And Maintenance Manual With Illustrated Parts List

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OM-2228 / Operation and Maintenance Manual
120CU20 / Series 500120 / 400 Hz. Generator Set
October 15, 2013 Chapter 2-2
Page 13
g) Filling the Cooling System.
The preparation and monitoring of coolant in liquid-cooled engines is especially important because
corrosion, cavitations, and freezing can lead to engine damage. For coolant system protection details
see the engine manufacturer’s operations manual.
(1) To Add coolant
a Remove radiator cap. Be sure that both radiator drain valves are closed.
b Pour coolant into radiator very slowly until it reaches the bottom of fill neck. Allow time for
trapped air to escape from the system then continue filling until the coolant level remains at
the bottom of the fill neck.
c Start the engine, bring it up to rated speed, and allow the thermostat to open. Add coolant as
trapped air escapes from the system and the coolant level falls.
d Continue to check coolant level until all trapped air escapes. Add coolant if needed to fill to
the bottom of fill neck. Re-Install radiator cap.
(2) Inspection/Check
a Check system for evidence of leaks.
b Inspect all hoses. Install new hoses as necessary. Tighten hose clamps as required.
c Check the condition of fan and water pump belts. Replace belts if necessary.
NOTE: It is good practice to attach a card, indicating the cooling system contents and date serviced,
to the radiator filler neck.
h) Thermostat.
The thermostat should be checked each fall, or as required. Refer to engine manufacturer’s
operations manual for recommended instructions.