TM 5-3805-280-24-1
Tests
LOWER BOOM WITH ENGINE STOPPED
(WHEN NOT EQUIPPED WITH BOOM
CYLINDER LOAD LOWERING VALVE)
SPECIFICATIONS
Boom Manual Lower Screw
6.9 Nm (60 lb-in.)
Boom Manual Lower
13 Nm (115 lb-in.)
Screw-to-Housing Nut Torque
SERVICE EQUIPMENT AND TOOLS
4 mm Hex Key Wrench
13 mm Combination Wrench
When an engine stops during operation, the boom cannot
be lowered using the pilot controller because there is no
pilot pressure oil to move the boom valve spool.
1. Remove the control valve access cover.
CAUTION: To avoid injury from escaping fluid
under pressure, never loosen screw more than
two turns as screw may come out. Tighten
screw and nut before applying pressure.
Prevent possible injury from unexpected
9025
machine movement. Clear all persons from the
25
area before lowering the boom with the engine
39
stopped.
2. Loosen the small nut (B) on the boom reduced leakage
valve housing (C).
Slowly loosen boom manual lower screw (A) 1/2 turn
using a 4 mm hex key wrench. The boom will start to
lower.
The boom lowering speed can be increased somewhat
Boom Manual Lower Screw
by loosening screw an additional 1-1/2 turns. Never
loosen screw more than two turns.
A--Boom Manual Lower Screw
B--Small Nut
C--Boom Reduced Leakage Valve Housing
3. After bucket is lowered to the ground, tighten the screw
to specification, and then the nut.
Continued on next page
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