HIGHWAY DRIVING (CONT)
The tractor operator must drive slowly and maintain constant visual contact with
spotter or injury to personnel may result.
When manually steering semitrailer, make many starts and stops to give spotter
time to adjust steering. The tractor operator should allow even space on both
sides of the tractor so that spotter steering semitrailer has room to make
adjustments or. injury to personnel and damage to equipment may result.
f. Manually steering semitrailer. If tractor/semitrailer is in an area with limited turning ability, semitrailer can be
manually steered to allow clear passage. A spotter, located at the semitrailer hydraulic control panel, can steer
semitrailer (para. 2-21) left or right to make room for tractor/semitrailer to pass through a tight area.
g. Stopping. Brakes on the tractor and semitrailer are applied at the same time during normal operation when driver
steps on tractor brake pedal. Brake pressure should be applied gradually and smoothly. Road conditions and
good judgment should be used while stopping. Always use caution on steep downgrades and slippery surfaces.
Make sure that the trailer hand brake control (Johnny Bar) in the tractor cab is
completely released prior to applying the tractor parking brakes or loss of
semitrailer reserve air supply may result.
If a hissing sound is heard from tractor parking brake control valve after setting
parking brakes, brake pedal must be released and trailer air supply control in
tractor must be pushed in and then pulled out.
h. Parking. When the tractor/semitrailer combination is to be parked and left unattended, make sure the trailer hand
brake control (Johnny Bar) located on the steering column in tractor cab is completely released; then, set parking
brakes. Be sure tractor engine and semitrailer APU are shut down. If hissing sound is heard from tractor parking
brake control valve after setting parking brakes, release tractor brake pedal; push in, then pull out trailer air supply
control in tractor. Chock wheels on tractor and semitrailer. For specific details on parking, refer to paragraph