C3, TM 9-2320-211-20
Section XXX. MAINTENANCE OF COMPRESSED AIR SYSTEM
a. Components. Air system components consist of
two air reservoirs, a hand-control valve, an air
the braking of a towed vehicle. Dummy couplings and
air supply valves, and air lines and fittings. One of the
flow when the system is not connected to another vehicle
cylindrically-shaped air reservoirs, the lower one, has a
and / or air system. The compressed air flows from one
safety valve which automatically opens when air pressure
component to another through copper tubing lines. Each
reaches 150 psi. This lower reservoir also contains a cock
line has threaded fittings at both ends. One check valve
reservoirs.
(3, fig. 2-188) and three double check valves (20, fig. 2-
b. Operation. Compressed air from one vehicle's
188) automatically regulate air flow throughout the
system is transferred into another vehicle's air system (or
system. Two sypply valves (10, fig. 2-188) are in the line
into the trailer airbrake system) through trailer brake
from the upper reservoir to an air governor (7, fig. 2-188).