TM 9-2350-256-20
CHAPTER 2: VEHICLE MAINTENANCE INSTRUCTIONS
2-17 HYDRAULIC TROUBLESHOOTING-Continued
HOISTING BOOM-Continued
A Attempt operation of the hoist winch, main winch,
and spade. If hoist winch, main winch, and spade
do not operate, troubleshoot main hydraulic system
and/or auxiliary hydraulic system. If hoist winch,
main winch, and spade operate go to step B.
B Visually inspect for damage. If damage exists and
boom cannot be repaired, replace hoisting boom (see
paragraph 11-11). If signs of damage exist and can
be repaired, notify Direct Support Maintenance. If
no signs of damage exist, go to step C.
C Visually inspect for any indication of class III oil leak
at stayline cylinder and actuating cylinder hydraulic
connections. If class III oil leaks are present, tighten
fittings (see paragraph 12-1). If no leaks are present,
go to step D.
Do not attempt to loosen or tighten
hydraulic fittings or lines when system is
pressurized. Severe injury or death to
personnel may result.
D Inspect for any
damaged or restricted hoses.
Replace hoses as necessary (see paragraph 12-1). If
no damaged or restricted hoses exist, go to step E.
E Visually inspect for failed or missing boom or
hydraulic cylinder attaching pins. If any failed or
m i s s i n g p i n s e x i s t ,
n o t i f y D i r e c t S u p p o r t
maintenance. If no failed or missing pins exist, go to
step F.
Test equipment must be able to withstand
1950-2050 psi (13,445-14,135 kPa),
Improper test equipment could burst during
testing and cause personnel injury or death.
F Test for boom combination control valve failure.
Perform STE/ICE-R Test No. 51 with 0-10,000 psig
pressure transducer (Appendix C, item 51) installed
in pilot-operated relief and unloading valve gage
port. With the main hydraulic system operating,
actuate boom combination control valve lever. If
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