Grade gripper solenoid, replacement

Bulletin number

FSB 593-013A

Component

Power train

Summary

Grade gripper solenoid, replacement. On some mack chu, cxu, gu, and td truck models built between 04/31/2008 and 11/30/2015, the solenoid valve for the grade gripper feature is prone to internal contamination in harsh environments. The internal contamination of the solenoid valve is caused by the buildup of grime, salt, road debris and other solid contaminants. In some cases, the buildup of solid contaminants caused the solenoid valve to malfunction. A similar malfunction is possible if the solenoid valve is equipped with a vent fitting that freezes over. The malfunction causes the trailer brake circuit to maintain trailer brake pressure after a grade gripper event.

Owners of these vehicles have filed 3 complaints in the transmission category.