LO 11-8 Outline maintenance procedures and identify tools and methods used to perform maintenance on a diesel engine cooling system

Maintenance Tips

The unique requirements of diesel engine cooling systems make it important to keep in mind a number of points when servicing diesel engine cooling systems. These include:

• The cooling system must be maintained on a regular basis to prevent overheating, cavitation, corrosion, scale, and gelation due to silicate dropout.
• Cracked cylinder heads and leaking head gaskets can cause coolant to leak into the engine, leading to catastrophic engine failure.
• Overconcentration of DCA or overconcentrated antifreeze can lead to silicate dropout.
• Conventionally formulated coolant should be changed and the cooling system flushed every 2 years.
• Corrosion-inhibitor packages contained in engine coolant can be damaged through overheating and should be discarded and not reused.
• It is recommended to pressure test cooling systems at 15–18 psi (103–124 kPa) to check for leaks. The pressure should hold for several minutes without significantly dropping. The engine should be inspected for external leaks after pressure testing. The adapter circled in Figure 3 is used with the pressure tester to check the radiator cap. The radiator cap should only release pressure at the rating on the cap.
• The concentration of antifreeze should be checked not only to ensure freeze protection but also because adequate antifreeze is needed to provide enough corrosion and cavitation inhibitors to the cooling system.