LOWER BOOM WITH ENGINE STOPPED
(WHEN NOT EQUIPPED WITH BOOM
CYLINDER LOAD LOWERING VALVE)
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.
CAUTION: To avoid injury from escaping fluid
under pressure, never loosen boom manual
lower needle valve more than 4 turns from
closed position, as valve may come out of
housing. Tighten valve and nut before applying
Prevent possible injury from unexpected
machine movement. Clear all persons from the
area around machine before lowering boom
with engine stopped.
1. Remove the control valve access cover.
2. Loosen nut (C).
3. Check that area around machine is clear of all persons
before lowering boom.
Slowly, loosen boom manual lower needle valve (B)
1/2--1 turn. The boom will start to lower.
Turn needle valve out more to increase boom lowering
speed or in to decrease lowering speed. Remember,
no more than 4 turns from the closed position.
4. After bucket is on the ground, first tighten needle valve
(B) then nut (C).
Boom Manual Lower Needle Valve-to-Housing--Specification
Torque .......................................................... 5.9--9.8 N·m (4.4--7.2 lb-ft)
A--Boom I Section
B--Boom Manual Lower Needle Valve
D--Boom Reduced Leakage Valve
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