TRACTOR/SEMITRAILER COUPLING/UNCOUPLING (CONT)
If tractor has been coupled to an offset angle, manually steer wheels to the
appropriate direction or damage to equipment may result.
(16) Have tractor operator attempt to pull forward against semitrailer to ensure kingpin is locked into tractor fifth
(17) Set parking brake on tractor. Chock tractor tires. Make sure wheel chocks for semitrailer are in place and
(18) Disconnect both air lines from tractor dummy couplings. Remove dummy couplings from semitrailer air
connectors. Apply small amount of grease (item 12, appx. E) on all rubber grommets. Connect air brake
system from tractor to semitrailer by mating service (blue) air connectors (12) and emergency (red) air
(19) Disconnect electrical connector from tractor electrical dummy coupling. Raise cover to 12-pin electrical
connector (14) and connect tractor electrical cable to electrical connector (14).
(20) Have spotter check steering wedge (2) alinement in tractor fifth wheel (4). If necessary, signal spotter to
reposition steering wedge (2).
Make sure the person adjusting the steering wedge adjusting nut is clear when the
steering wedge is cycled back and forth or injury to personnel may result.
(21) Turn adjusting nut (10) clockwise until steering wedge (2) tightens securely into fifth wheel (4). Have spotter
continually operate steering valve (9) slightly left and right and tighten adjusting nut (10) to remove all play.
(22) Push in trailer air supply control in tractor to provide air to semitrailer air brake system.
(23) Allow ample time for air tanks to charge and then apply brakes to ensure that brakes are working properly.
Apply tractor parking brakes.
(24) Raise front and rear support legs (para. 2-22 and 2-23). Remove and stow tractor and semitrailer wheel