COVER AS 2018802 - Caterpillar

19. Add and maintain the coolant level to the proper level on the sight glass, if equipped. To prevent engine damage, never add coolant to an overheated engine. Allow the engine to cool first. 20. Check the condition of the fill cap gasket. If the gasket is damaged, discard the old fill cap and install a new fill cap.If the gasket is not damaged, use a 9S8140 Service Tool to pressure test the fill cap, if applicable. This tool is available from your Caterpillar dealer.The correct filler cap pressure is stamped on the face of the filler cap. If the filler cap does not hold the correct pressure, install a new filler cap.21. Stop the engine.Replace Water Temperature Regulators (Thermostats)
Replacing the four thermostats prior to failure is a good preventive maintenance practice because it reduces the chances for unscheduled downtime. Failure to replace thermostats on a regularly scheduled basis could cause severe engine damage to cooling system and other engine components.Since Caterpillar engines incorporate a shunt design cooling system, it is mandatory to always operate the engine with four thermostats.If the thermostats fail in the closed position, it will cause excessive engine overheating. Excessive overheating could result in cylinder head cracking or piston seizure problems. Excessive oil overheating could result in damage to the engine by accelerating piston ring and cylinder liner wear.If thermostats fail in the open position, it will cause the engine oil and operating temperature to be too low during partial load operation. Low engine oil and operating temperatures during partial loads could cause an excessive carbon build-up inside the cylinder. This excessive carbon build-up could result in accelerated piston ring and cylinder liner wear.Depending on load, thermostats that fail in a partially opened position will cause either an overheating or an overcooling condition.Caterpillar recommends the replacement of the four thermostats on a regularly scheduled basis to be the most cost effective way to operate the engine.Refer to the Service Manual for disassembly and assembly procedures to replace the thermostats as required in the Maintenance Management Schedule. Contact your Caterpillar dealer for assistance.Jacket Water Pump, Turbochargers and Starting Motors
Rebuild or Exchange
One unscheduled failure caused by any of these components will cost more in downtime than maintaining them before failure. The cost incurred to maintain these components before failure as recommended, could be significantly less than if the component fails.The belief that it is more costly to maintain components before failure than it is to operate the engine until the component fails, is false.By maintaining these components before failure, unscheduled downtime will be minimized and the chances for potential damage to other engine parts reduced. The prevention of unscheduled downtime saves money and lowers operating costs.If the engine is operated until the component(s) fails, it could cause additional damage to the engine. For example: A failed water pump might cause severe engine overheating problems that could result in cracks in the cylinder head, a piston seizure or other potential damage to the engine; severe damage to