TM 55-2210-223-34
TO 45A2-2-14-22
4-12.
INDEPENDENT BRAKE VALVE (cont)
ASSEMBLY (cont)
38. Install spring housing (11) on valve body (2) and secure with four nuts (10). Turn adjusting screw (9) clockwise.
39. Check that cam (8) is in RELEASE position. Install handle (4) into slot of cam.
40. Pull back on handle retaining pin assembly (25) and check that full travel of handle is into cam. Release handle
retaining pin assembly.
41. Install valve body (2) and gasket (3) and secure with three nuts (1).
TEST
42. Test the independent brake valve in accordance with Test Specification T-2403. The independent brake valve
functions as follows:
a.
Make adjustment of delivery pressure at the adjusting screw on the control spring housing. If a higher pressure is
desired, increase the compression on the spring so that a higher delivery pressure will be required to lap the
valve portion. If a lower pressure is desired, decrease the compression on the spring so that a lower delivery
pressure will be required to lap the valve portion.
b.
The independent brake valve shall function as follows:
(1) The independent brake valve has two positions: RELEASE and FULL APPLICATION.
(2) When the handle is moved from RELEASE position toward FULL APPLICATION position, the valve
functions as follows:
(a) The valve handle actuates a cam which, in turn, positions a supply and exhaust valve assembly, first to
seat the exhaust valve and then to unseat the supply seat.
(b) Main reservoir air will flow past the unseated supply valve from port 30 to port 20.
Port
20
from
the brake valve is connected to port No. 2a on the 6-NFR distributing valve via the No. 24-A double
check valve.
(c) Pressure developed in port 20 will actuate the relay valve to develop pressure in the brake cylinders. As
air pressure develops in port 20, it also develops on the inner face of the diaphragm in the independent
brake valve.
(d) The buildup of pressure on the diaphragm is opposed by spring pressure on the opposite side; and when
the air pressure and spring become balanced, the valve assembly will move to its lap position in which
the supply valve becomes seated to terminate further flow of main reservoir air to port 20.
4-56
