TM 5-3805-262-34
3-12. AIR BRAKE SYSTEM MAINTENANCE (CONT)
b. Service Brake Treadle and Valve and Declutch Treadle and Valve. This task
covers disassembly, cleaning, inspection, and reassembly of service brake treadle
and valve and declutch treadle and valve. Theory of operation is also provided
below.
THEORY OF OPERATION (SHEET 1 OF 2)
The treadle and valves control flow of air to brake actuators. Each treadle and
valve has a rubber spring. As the pedal is pushed, force is put on the rubber spring
and then applied to the piston. When low or medium force is applied to the pedal,
the rubber spring is a flexible link between pedal and piston. This flexible link
lets the operator control pressure in the brake system with more accuracy. When max-
imum force is applied to the pedal, the rubber spring compresses completely so that
there is no flexible link. The brake actuator will receive the full pressure of the
air supply from the air reservoir.
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