FILM- 9X8540 - Caterpillar

(6HK),
789B (7EK),
793B (1HL) TrucksA new variable speed fan clutch group is available for 785B, 789B, and 793B Trucks. This new variable speed fan clutch group is controlled by the engine Electronic Control Module (ECM) and is belt driven by the crankshaft pulley.
The new ECM controlled variable speed fan clutch went into production beginning with the 785B (6HK523-Up), 789B (7EK392-Up), and 793B (1HL412-Up) Trucks. The new clutch group is adaptable to trucks that are equipped with the electronic unit injector (EUI) system.
For more information refer to Special Instruction REHS0023 entitled "New ECM Controlled Variable Speed Fan Clutch Group Available For 785B, 789B, And 793B Trucks".