B5.9G, B5.9LPG, B Gas Plus, B LPG Plus, and B Gas International Engines – 018-004   Coolant Recommendations and Specifications

Use low-silicate antifreeze that meets ASTM4985 (GM6038M specification) criteria.

Cummins Inc. recommends using either a 50/50 mixture of good-quality water and fully formulated antifreeze, or fully formulated coolant when filling the cooling system.

Good-quality water is important for cooling system performance. Excessive levels of calcium and magnesium contribute to scaling problems, and excessive levels of chlorides and sulfates cause cooling system corrosion.

Cummins Inc. recommends using Fleetguard® Compleat. It is available in both glycol forms (ethylene and propylene).

Fully formulated antifreeze must be mixed with good-quality water at a 50/50 ratio (40- to 60-percent working range). A 50/50 mixture of antifreeze and water gives a -36°C [-33°F] freezing point and a 108°C [226°F] boiling point. The actual lowest freezing point of ethylene glycol antifreeze is at 68 percent. Using higher concentrations of antifreeze will raise the freezing point of the solution and increase the possibility of a silica gel problem.

A refractometer must be used to accurately measure the freezing point of the coolant. Use Fleetguard® refractometer, Part Number C2800.

Do not use a floating ball hydrometer. Using floating ball hydrometers can give an incorrect reading.

Do not use sealing additives in the cooling system. The use of sealing additives will:

• Build up in coolant low-flow areas
• Plug the radiator and oil cooler
• Possibly damage the water pump seal.

Do not use soluble oils in the cooling system. The use of soluble oils will:

• Corrode brass and copper
• Damage heat transfer surfaces
• Damage seals and hoses.