In tractor/trailer combinations where the trailer parks on spring brakes: Applying park brakes will stop air being supplied from the tractor unit to the trailer. The Sidelifter requires an air supply to retract the crane module locking pins and operate the engine stop and speed control. Normally there is enough pressure remaining the the trailer air system to operate these controls provided there are no leaks in the air system. This caution does not apply to units where parking brakes are operated by applying air pressure to the service lines. |