TUBE AS 6I9458 - Caterpillar

Pressurized System: Hot coolant can cause serious burns. To open the cooling system filler cap, stop the engine and wait until the cooling system components are cool. Loosen the cooling system pressure cap slowly in order to relieve the pressure.
This engine has a pressurized cooling system. A pressurized cooling system gives two advantages:
The pressurized cooling system can operate safely at a higher temperature than the boiling point of water at a range of atmospheric pressures.
The pressurized cooling system prevents cavitation in the water pump.Cavitation is the sudden generation of low pressure bubbles in liquids by mechanical forces. The generation of an air or steam pocket is much more difficult in a pressurized cooling system.Regular inspections of the cooling system should be made in order to identify problems before damage can occur. Visually inspect the cooling system before tests are made with the test equipment. Visual Inspection Of The Cooling System
Check the coolant level in the cooling system.
Look for leaks in the system.
Inspect the radiator for bent fins and other restriction to the flow of air through the radiator.
Inspect the drive belt for the fan.
Inspect the blades of the fan for damage.
Look for air or combustion gas in the cooling system.
Inspect the radiator cap for damage. The sealing surface must be clean.
Look for large amounts of dirt in the radiator core. Look for large amounts of dirt on the engine.
Shrouds that are loose or missing cause poor air flow for cooling.