Unic URW295CUR - 5-Section Boom (Triple Cylinders) Troubles

5-section boom (Triple cylinders)
Troubles Possible cause Measures to be taken
Retraction is normal, but when
extending, booms (2) and (3)
extend at the same time, in
other words disorderly.
Some foreign substances are
clogging the part of selec-
tor valve of telescoping cylin-
der (1).
Disassemble selector valve for
cleaning, or replace it with a
new one.
Extension is normal, but when
retracting, booms (3) (4) and
(5) retract at the same time,
in other words disorderly.
Some foreign substances are
clogging the part of selec-
tor valve of telescoping cylin-
der (2).
Extension is normal, but when
retracting, booms (3),(4)
and (5) retract at the same
time, in other words
disorderly .
Some foreign substances are
clogging the part of selec-
tor valve of telescoping cylin-
der (2).
Snap ring at the part of
selector valve of telescoping
cylinder (2) got out of place.
Disassemble selector valve for
cleaning, or replace it with a
new one.
Rearrange snap ring.
Extension is normal, but
when retracting, booms (2)
and (3) retract at the same
time, in other words disor-
derly.
Some foreign substances are
clogging the part of selec-
tor valve of telescoping cylin-
der (1).
Snap ring at the part of
selector valve of telescoping
cylinder (2) got out of place.
Boom (2) extends but boom
(3) does not extend.
Nut at slide pipe of telescop-
ing cylinder (1) was loosened.
cylinder (1) and tighten the
nut.
Boom (2) and (3) extend,
but boom (4) and (5) does
not extend.
Nut at slide pipe of telescop-
ing cylinder (2) loosened.
cylinder (2) and tighten the
nut.
After full extension, booms
(5) retracts but boom (3)
does not retract.
Adjusting bolt pushing the
spool of selector valve of
telescoping cylinder (2) was
loosened.
Selector valve spool of tele-
scoping cylinder (2) was bent.
Adjust the bolt.
Replace selector valve ass'y
with a new one.
Boom (3), (4) and (5)
retracts but boom (2) does
not retract.
Adjusting bolt pushing the
spool of selector valve of
telescoping cylinder (1) was
loosened.
Selector valve spool of tele-
scoping cylinder (1) was bent.
Note: During operation test after disassembling and repairing, the reason why the booms (4), (5)
and (6) stop extending halfway is presumed that the left and the right wire ropes for
extension were crossed when reassembling.
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Disassemble telescoping
Disassemble telescoping
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