TM 9-2330-227-14&P
EQUIPMENT DATA - CONTINUED
Tabulated Data - Continued
2021.7 cubic feet (CU ft)
Shipping Cubage
(56.6 cubicmeters (m3))
Towing Vehicle
2 1/2 ton, 6x6 (2.27 mtons)
Maximum Towing Speed
Cross country M146
30 miles per hour (mph) (48 kilometers
per hour (km/h))
50 mph (80 km/h)
Highway
Tire Pressure
Highway driving
50 pounds per square inch (psi)
(345 kilopascals (kPa))
35 psi (241 kPa)
Cross country driving
15 psi (103 kPa)
Sand driving
Section III. PRINCIPLES OF OPERATION
Page
Page
Electrical System . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-10
Air Over Hydraulic Brake System . . . . . . . . . . . . . . . 1-9
AIR OVER HYDRAULIC BRAKE SYSTEM
Towing vehicle air pressure is sent through the emergency air line to the emergency relay valve and
then to the air reservoir. When towing vehicle brakes are applied, air is sent through the service air
line to the emergency relay valve. The relay valve then releases air from the reservoir to the air
chamber. Air pressure behind the chamber diaphragm pushes the piston in the master cylinder
which forces hydraulic fluid through the lines to the brake cylinders. The cylinders force the
brakeshoes against the brakedrum. Brakeshoe and drum friction slows, stops, and holds the
semitrailer until the brake pedal is released, allowing applied air to vent.
1-9