OUTER BOOM MAINTENANCE - CONTINUED
Do NOT remove hydraulic tank filler cap or disconnect or remove any hydraulic system line or fitting
unless hydraulic system pressure has been relieved. Hydraulic system pressure can be over 3000 psi
(20685 kPa), even with engine and pump OFF. To relieve pressure, lower all hydraulic attachments to
the ground and shut down engine. Move control levers through all operating positions, then SLOWLY
loosen hydraulic tank filler cap. After maintenance, tighten all connections before applying pressure.
Escaping hydraulic fluid under pressure can penetrate the skin, causing injury or death.
Before performing step 2, make sure lines and extend cylinder hoses under boom are closed securely
using metal plugs. Hydraulic oil under pressure can spray from hoses and lines causing bodily injury if
lines and hoses are not closed securely.
Wipe the area clean around all hydraulic
connections to be opened during removal
and disassembly. Cap oil lines and plug
holes after removing lines. Contamination
of the hydraulic system could result in pre-
If more than one hydraulic line is to be
removed, tag lines to assure proper instal-
lation. Use suitable container to catch any
hydraulic oil that may drain from system.
Start engine and raise outer boom (3) as necessary to
access hoses (1 and 2). Stop engine (TM 10-3930-660-
Disconnect hoses carefully during step 3.
Hydraulic oil may be under pressure. Fail-
ure to follow this precaution will cause
Tag and disconnect three hoses (1) from lines (4) at
bulkhead. Plug three hoses (1) with metal caps.
Remove capscrew (5), four clamp halves (6) and nut
(7) securing two hoses (2). Leave hoses (2) plugged
with metal caps.