TM 9-2330-294-14
air to inflate tires or for powering auxiliary air
for transporting light payloads up to 15 tons and
equipment. Air system pressure can be checked at
provides 15 psi air pressure in the air springs.
the auxiliary air supply valve using the towing
(4) No load (lift ). The no load position is used
vehicle tire air pressure gage. The air system
when it is desired to operate semitrailer with axles 7
reservoirs can be pressurized through the auxiliary
and 8 raised and provides 100 psi air pressure in the
air supply valve.
air axle lift assemblies. The semitrailer may be
operated fully loaded with handle in this position
2-9. Brake Air
Line Couplings
only if necessary to negotiate a tight turn at speeds
below 5 mph. After completing turn, return handle
The "SERVICE" and "EMERGENCY" air line
couplings are mounted on the top front of the
c. Air Shutoff Valves. There are four air control
gooseneck. These couplings are used to supply air
shutoff valves for the air suspension system. These
pressure from the towing vehicle and to control the
valves enable the operator to cut off the air to a
semitrailer brakes. After the dummy couplings are
specific air suspension system component in case of
removed, the intervehicular air hoses from the
damage. The valves control air to the following
towing vehicle may be connected to the semitrailer
components: axle 7 air lift (A); axle 8 air lift (B); axle
couplings. When semitrailer air line couplings are
7 air springs (C); axle 8 air springs (D).
not in use, the two dummy couplings should be
connected to prevent entry of foreign matter into the
CAUTION
air system.
If air suspension supply valve(s) are shut off
2-10. Air
Reservoir Drain Cocks
because of air leak or damage, reduce speed
and avoid operating vehicle on terrain that
A drain cock is located on the underside of each air
will add excessive strain to the suspension
reservoir. The drain cocks are accessible from un-
system. Do not exceed 10 mph. Have
malfunction remedied by maintenance
derneath the semitrailer and should be opened to
drain the system of air prior to repairing air system
personnel at the earliest opportunity.
components. Each drain cock should be opened daily
If air leak or damage occurs at any of these com-
before and at the end of semitrailer operation to
ponents, shut off air supply to affected component
by moving pertinent shutoff valve handle clockwise.
drain accumulated water from the reservoirs. Be
certain each drain cock is securely closed after
2-8. Auxiliary Air Supply Valve
draining accumulated water. Semitrailers No. 1
through 200 are equipped with four drain cocks and
The auxiliary air supply valve is located on the left
semitrailers No. 201 and on have three,
side of the semitrailer to the rear of the suspension
air control valve. It provides a source of compressed