TM 5-3810-307-24-1-1
Operating and Leakage Checks
7.
With the air system fully charged and the
parking control valve in the release position, coat the
1.
Chock the vehicle wheels.
exhaust port and the area around the valve corner
with a soap solution. Slight leakage is permitted.
2.
Charge the air systems to the governor cut-out
pressure.
8.
If the spring brake control valve does not
function as described above, or leakage is
3.
Place the parking control valve in the park
excessive, it is recommended that it be repaired or
position. Observe the spring brake actuators apply
replaced Refer to the Parts Manual for repair parts.
promptly. In the delivery port of the valve, install a
test gauge known to be accurate. Place the parking
PRESSURE REDUCING VALVES
control valve in the release position. Observe the
spring brake actuators release fully.
Removal
4.
With the parking control valve in the release
1.
Chock the wheels.
position, note the gauge pressure reading. It should
be approximately 45 psi (310 kPa). If the pressure
2.
Deplete the pressure in both air systems.
reading is incorrect, the valve must be repaired or
replaced.
3.
Disconnect and tag the air lines from the valve
and remove the valve.
5.
Place the parking control valve in the park
position The gauge reading should drop to zero
Installation
promptly A slow release of pressure could indicate
faulty operation of the single check valve (within the
1.
Install the fittings and air lines to the valve as
modulating valve).
tagged during removal.
6.
Place the parking control valve in the release
position. Locate the No 1 service reservoir and drain
it completely. Then, apply the foot brake valve
several times and note that the pressure reading on
the gauge decreases each time the foot brake valve
is applied. After the foot brake valve has been
applied several times, pressure on the gauge will
drop to the point where release of the spring brake
actuators will no longer occur.
2-7-31 C-1
