TM 5-3655-210-12
Figure 4-75. Wheel brake assembly
be applied to coverplate, coverplate vent, and exhaust
line is charged. However, remember that under these
port of valve to detect possible inlet valve, inlet valve
conditions, the trailer emergency line will not be charged
guide grommet and emergency piston grommet
until the tractor pressure increases to the point, of
leakage. A combined leakage as indicated by a one-
opening the emergency valve in the tractor protection
inch (2.54 cm) soap bubble in not less than 5 seconds is
valve if installed. Note further that this brake application
permissible. No leakage is permissible at pipe plugs or
is completely released as trailer emergency line
fittings.
pressure reaches approximately 60-65 psi (4.2184.5695
(3) Make and hold a full service brake
kg per sq cm).
application with system reservoir pressure stabilized at
(2) Fully charge tractor and trailer air brake
90100 psi (6.327-7.03 kg per sq cm) with engine
systems. Make several service brake applications and
stopped. A two minute check should result in no more
check for prompt braking response at all trailer wheels.
than an eight pound pressure drop for the combination
With brakes released and system reservoir pressure
vehicle system.
If this check indicates possible
stabilized at 90-100 psi (6.327-7.03 kg per sq cm), with
excessive leakage of valve, soap suds should be
engine stopped, a two minute check should result in no
applied to cover plate, cover plate vent, and exhaust
more than a six pound pressure drop for the
port to detect exhaust valve, valve guide grommet,
combination vehicle system. If this check indicates
possible excessive leakage of valve, soap suds should
4-83
