LINE ASSEM. (No. 1) 8N4221 - Caterpillar

Stop the engine and allow the engine to cool. Loosen the cooling system filler cap slowly to relieve any pressure. Remove the cooling system filler cap.Note: Refer to Operation and Maintenance Manual, "General Hazard Information" for information on Containing Fluid Spillage.
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Typical example
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Remove the drain plug (1) on the engine. Open the drain cock or remove the drain plug on the radiator.Allow the coolant to drain into a suitable container.
Properly dispose of the drained material. Obey local regulations for the disposal of the material.
Dispose of used engine coolant properly or recycle. Various methods have been proposed to reclaim used coolant for reuse in engine cooling systems. The full distillation procedure is the only method acceptable by Caterpillar to reclaim the used coolant.
Flush
Flush the cooling system with clean water to remove any debris.
Clean the drain plugs. Install the drain plugs. Refer to Torque Specifications, SENR3130 for more information on the correct torques.
Do not fill the cooling system faster than 5 L (1.3 US gal) per minute to avoid air locks.Cooling system air locks may result in engine damage.
Fill the cooling system with a mixture of clean water and Caterpillar Fast Acting Cooling System Cleaner. Add 0.5 L (1 pint) of cleaner per 15 L (4 US gal) of the cooling system capacity. Install the cooling system filler cap.
Start and run the engine at low idle for a minimum of 30 minutes. The coolant temperature should be at least 82 °C