Cooling System

This section includes information on the following:

  • Changing coolant at the end of the coolant drain interval.
  • Changing coolant types.
  • Cooling system contamination.

Coolant Change

  • At the end of a coolant drain interval, remove the used coolant by following the drain procedure provided in the engine service literature and re-fill with fresh coolant.
  • Note that not all drain procedures for a specific application have the ability to drain all of the used coolant from the cooling system. For these applications, a drain and flush process might be needed to ensure as much used coolant is removed from the cooling system before installing new coolant. A drain and flush process includes draining as much coolant out of the system as possible and thoroughly flushing the system with de-ionized water or water that meets water requirements outlined in Appendix B, Appendix B - General Coolant Information.
  • When new coolant is installed, circulate the system should and use a refractometer to ensure the new coolant is not diluted with residual water from the flush process. For example, if enough residual water is in the system, use concentrated coolant to re-balance the concentration so the desired ratio for your application is reached. Circulate the system and use a refractometer to recheck the concentration. The suggested mixing ratio is 50/50 (50% antifreeze / 50% water) for regular climate or 60/40 (60% antifreeze / 40% water) for colder climates.

Changing Coolant Technologies

  • Follow cooling system flushing recommendations outlined in Coolant Change section.
  • To ensure there is no mixing between the old technology and new technology, full chemical analysis should be conducted.
  • If possible, coordinate with your coolant supplier for additional support when changing coolant technologies.

Cooling System Contamination

  • Follow cooling system flushing recommendations outlined in Coolant Change section.
  • If a coolant system failure occurs that results in coolant contamination, a complete cooling system flush is required. If the contamination cannot be removed via a clean water flush, a cooling system cleaner can also be used. Please contact the DTNA Aftermarket for available cooling system cleaning products.
  • If a cleaner is used, it is important to complete a chemical analysis to ensure there is no interaction between the newly installed coolant and any residual cleaner from the flush process.
  • If possible, please work with the cleaner supplier for additional support when using a cooling system cleaner.

Document Number:0000008076