https://www.truck-manuals.net/mack/ 72 INSTRUMENTS AND CONTROLS
CAUTION When preparing to connect a tractor to a trailer, make sure that the height of the 5th wheel matches the height of the underside of the trailer. Failure to do so will result in the trailer being improperly connected. After the trailer has been coupled and the trailer landing gear has been raised, make sure that the 5th wheel jaws have properly engaged the trailer king pin, and there is no gap between the 5th wheel plate and the bottom of the trailer.
CAUTION DUMP BODY: Always exhaust the air from the bags before raising the dump body to protect the air bags and improve chassis stability while dumping. If the dump body is raised while the air suspension is pressurized, damage to the air bags may result.
CAUTION Do not drive the vehicle with the air bags exhausted. Repressurize the air bags before driving the vehicle.
• Automatic Traction Control Switch/Heavy Mud/Snow – Activate for increased traction control in heavy mud or snow. (See “Automatic Traction Control (ATC) (If Equipped)”, page 134 in the OPERATION section of this manual for more details.) When the operator presses the top of the rocker switch, the heavy mud/snow function ATC indicator lamp blinks continuously. The ATC lamp stops blinking when the ATC mode switch is pressed again or ignition key cycled.
CAUTION Be sure to deactivate the heavy mud/snow function when no longer needed. Continued operation with the heavy mud/snow function active will result in vehicle damage. If after a reasonable amount of time (no more than five minutes) the vehicle is still not moving, deactivate the ATC and put on chains.
