TM 9-2330-381-14
2-8.
PNEUMATIC CONTROLS
WARNING
With semitrailer uncoupled and gladhand dummy couplings installed, ensure that
vented dummy coupling is installed on the emergency (red) gladhand prior to
releasing brakes with the brake release valve. If a nonvented dummy coupling is
installed, the parking brakes cannot be reapplied and injury to personnel may
result.
BRAKE RELEASE VALVE (1). A push/pull type valve used to disengage the parking brakes when the semitrailer is not
connected to a tractor. Push in the handle to charge air pressure and release the parking brakes. Pull out to release air
pressure and engage parking brakes. This valve can only be cycled a few times before the air supply in the air tanks
must be replenished.
AIR TANK DRAIN VALVES (2). There are five air tank drain valves on this semitrailer. Three are located on curbside of
platform and two are located on streetside of platform. These drain valves are used to drain either moisture or air
pressure from air tanks. Pull and hold the lanyard until moisture is no longer being discharged or until all air in that tank is
released.
2-12 Change 1
