Usage:
771D (6YS),
775D (8AS) Quarry Trucks;
769D (5SS),
773D (7CS) Off-Highway Trucks
Description of Change: The self test feature of the supplemental steering on the 769D through 775D Off-Highway Trucks has changed. Under certain conditions the self test may not activate.
The new electronic control system uses a pressure switch instead of a flow switch to control the activation of the supplemental steering pump motor. If pressure is present in the steering system when the key is turned on, the supplemental steering system will skip the self test in which the pump is cycled on for several seconds. Skipping the self test is normal under these conditions and may be the result of the key being turned on again after the truck was running in the last few minutes.
To ensure the system is operating properly, allow the truck to stand with the engine off for ten minutes or turn the steering wheel with the engine not running to remove any residual system pressure. Turning the key on will then cause a momentary operation of the supplemental steering pump.
Adaptable To: Effective with 771D (6YS1), 775D (8AS1), 769D (5SS1) and 773D (7CS1).