TM 9-2320-272-24-1
1-23. COMPRESSED AIR AND BRAKE SYSTEM OPERATION (Contd)
Key Item and Function
A AIR DRYER - Installed in supply line to wet tank and removes moisture from inlet air to wet tank
(M939/A1 air dryer kit installed only).
wet tank reservoir.
C SAFETY VALVE - Located at inlet side of wet reservoir, it prevents pressure buildup by releasing
air pressure exceeding 150 psi (1,034 kPa) when the governor fails to regulate air supplied by the
compressor.
D WET TANK RESERVOIR - Performs two functions:
Traps water in air reservoir to protect other air systems from freezing or corroding.
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Stores reserve air supply enabling operator to make normal stops when engine stalls or
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compressor fails.
E PRESSURE PROTECTION VALVE - Performs two functions:
Allows air pressure to build to 60-65 psi (414-448 kPa) before supplying air to auxiliary air-
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powered equipment.
Closes off auxiliary air system from other systems if an accessory fails and prevents loss of air
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from secondary reservoir.
G WET TANK RESERVOIR DRAINVALVE - Provides a drain for moisture and air from reservoir.
H AIR DRYER - Removes moisture from inlet air to wet tank (M939A2 only).
compressor cycles.
builds to 120-127 psi (827-876 kPa), the governor will close valve.
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