There is no permanent solution yet for a problem with seal leakage on Cummins N14 engines using extended life coolants.

Operators of N14 engines factory-filled with Texaco's Extended Life Coolant and other similar formulations supplied by Equilon Enterprises LLC, an affiliate of Texaco are being told to add a one-time silicate supplement to the cooling system to deal with the situation.
Cummins believes this will reduce the risk of seepage through silicone rocker box gaskets which were being attacked by organic acids in the coolant after 80,000 to 100,000 miles. A special silicate supplement, Silicate Fluid for Cummins Engines Only, is being offered free of charge by Cummins.
N14 users can also add supplemental coolant additives (SCAs) equivalent to three additions of DCA or a Penray equivalent product to gain the same protection. However, if less than three additions have been used, the recommendation is to go with the specially formulated silicate.
Cummins officials say they have no plans to change the rocker box gasket material. "Our N14 engines have the lowest warranty costs of our automotive engine line. We see no reason for Cummins to make any gasket material changes," a Cummins executive said.
The seal degradation is restricted to Cummins N14 engines only and does not affect other Cummins models or other engine makes.
International is the only truck OE which uses the extended life coolant as standard factory fill and it's only on 9000 series truck models with Cummins, Cat and Detroit power. Trucks built after July 12, 1999 with Cummins power switched back to traditional fully formulated coolant. Cat and Detroit powered trucks continue to get the long life coolant as standard. All the other truck manufacturers use traditional coolants as standard fill but offer the organic extended life coolant as an extra cost option.
If have any questions about ordering the silicate additive, call 800-346-9041. For technical questions, call 800-782-7852 option 3.