Cummins Claims An Extended-Life Coolant Damages Seals, Engines

Cummins Engine Co. says a brand of extended-life coolant is causing problems for its engines, and has formed a task force with the suppliers of the coolant to seek “long- and short-term solutions.”

The engine manufacturer is working with Texaco and Equilon Lubricants to provide customers with means to prevent problems that have been associated with Texaco Extended Life Coolant.

Sources at Cummins said the coolant, when used to fill engines at the factory, has been found to affect the silicone gaskets and cause leakage and engine failure.

The coolant is of a type known as organic acid. Cummins sources said they became aware of the problem when they noticed “jellification” of new oil, which indicates that the oil is being contaminated with coolant.

Detroit Diesel, which markets the same kind of coolant under the name Power Cool Plus, says the product is safe for its engines.

John Ruck, director of parts marketing at Detroit Diesel, said the lack of silicates in the coolant apparently causes the gasket problem. He said Detroit Diesel does not use silicone gaskets.

In a letter to Cummins customers, Texaco and Equilon supported the engine maker’s position that its engines should be factory filled with “conventional coolant technology.”

For Cummins engines already containing Texaco Extended Life Coolant, the task force has recommended the addition of concentrated silicates or the installation of a coolant filter containing silicates.

Concentrated silicates will be available free from Equilon in early September, along with instructions for their use. The letter cautioned that “over-treatment of silicates in the cooling system can be damaging to other components.”

Equilon was said to be working with manufacturers to supply coolant filters that contains silicates.