TM 9-2330-381-14
GOOSENECK ISOLATION VALVE (7). A series of ball valves which are used to isolate the gooseneck hydraulic
cylinders from the suspension equalization system. When the gooseneck needs adjusting or the semitrailer is being
uncoupled from a tractor, the gooseneck isolation valve handle must be pulled outward (ADJUST) to prevent the
gooseneck from falling and damaging any equipment. When coupled to a tractor, normal position for this valve handle is
the RUN (inboard) position. When uncoupled from a tractor, normal position for this valve is in the ADJUST (outward)
position. This valve must be operated only when coupling/ uncoupling the semitrailer from a tractor or when gooseneck
adjustments are required while uncoupled from a tractor. This valve handle must be placed in RUN position for driving. If
semitrailer is to be parked/stored uncoupled from a tractor, the gooseneck must be completely lowered before moving
valve handle from ADJUST to RUN position.
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