TM 9-2320-272-10
2-26.
OPERATION OF TRACTOR AND FIFTH WHEEL (Contd)
(9)
Press in trailer air supply valve (3) and
hold in place for 15 seconds. Release valve (3). Valve
(3) should remain in engaged position indicating
semitrailer airbrake system has proper air pressure. If
valve (3) does not remain in engaged position,
disconnect couplings (9) and notify your supervisor.
(10) Pull down trailer air brake hand control
lever (2) to engage semitrailer brakes.
WARNING
Do not back up without a ground guide. Doing so may result in damage to vehicle, injury, or death.
(11) Release parking brake lever (6), place transmission selector lever (5) in R (reverse), and resume
backing up.
(12) Stop vehicle when coupling jaws (7) close around semitrailer kingpin (8). Visually check to make sure
jaws (7) have completely closed.
(13) With trailer air brake control handle (2) engaged, place transmission selector lever (5) in 1 (first) and
slightly depress accelerator pedal. Tractor will not move forward if fifth wheel is properly connected to semitrailer.
CAUTION
Stop vehicle immediately if tractor moves forward and repeat task c, steps 9 through 12.
(14) Place transmission selector lever (5) in N (neutral) and apply parking brake lever (6).
(15) Connect electrical cable (11) to electric receptacle (10) on semitrailer.
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