Section I. OPERATING PROCEDURES
damage. A plugged or inoperative vent can
cause extensive shell damage if design
pressure or vacuum is exceeded. The fus-
If incorrectly used, this equipment can cause
ible vents are designed to operate at high
severe injury or death. Those who use and
temperatures. If these vents are coated
maintain the equipment should be trained in
with paint, dirt, or other foreign material,
its proper use, should be warned of its
the temperature when relief occurs may be
dangers, and should read the entire manual
before attempting to set up, operate, adjust,
or service the equipment.
This is a brief service to make sure that the semi-
trailer is ready for operation, and that conditions affecting
the semitrailer's readiness have not changed since the
previous after-operation service. The before-operation
This section provides operator/crew instructions for
services specified in table 3-1, Operator/Crew Preventive
operation and proper use of the M967, M967A1, M969,
Maintenance Checks and Services, Chapter 3, must be
M969A1, M970, and M970A1 semitrailers. Operations
performed before using the semitrailers.
common to all six models are described first, followed by
those operations which pertain to a particular model.
You must follow approved practices and
precautions. A detailed study of Section III, Operation
Under Unusual Conditions, is essential for use of this
material under unusual conditions.
Coupling Semitrailer to Towing Vehicle
Frequent inspection of equipment, safety
devices, and working areas must be per-
Back the towing vehicle slowly to the front of the
formed to ensure personal and operational
semitrailer. Maneuver the towing vehicle so that the
safety and to correct potential or actual
kingpin on the semitrailer is in line with the fifth wheel
jaws on the towing vehicle. Before the upper coupler
The semitrailer must not be operated if any
(kingpin) plate of the semitrailer starts to ride on the fifth
of the following conditions exist:
wheel of the towing vehicle, stop the towing vehicle. Make
sure the kingpin and the fifth wheel are properly alined.
a. Fuel leaks.
Do not ram tractor into semitrailer pick-up plate. You may
need to raise or lower the landing legs to aline the level of
b. Damage to lighting fixtures, wiring or
the semitrailer kingpin plate with the tractor fifth wheel.
electrical conduits, or lights inoperative.
Back towing vehicle under upper coupler (kingpin) plate
c. Damage to towing vehicle or semi-
until the kingpin and fifth wheel hook automatically.
Make sure the kingpin and fifth wheel are engaged and
d. Primary or parking brake systems in-
couplings and emergency air couplings (fig. 2-1). Couple
e. Vents plugged, inoperative, or re-
the towing vehicle air line marked SERVICE and the air
moved. Pressure, vacuum, and fusible
line marked EMERGENCY to the semitrailer coupling
vents are installed to meet code require-
bearing a like tag.
ments and to protect the semitrailer from