Troubleshooting - Cascade High-Visibility Viewmast II 35C Service Manual

Section
4 Troubleshooting
The following table lists problems that may be encountered
on your Dual Viewmast II, the probable causes and the
recommended corrective action that should be taken to
restore the mast to normal operating condition.
PROBLEM
PROBLEM CAUSE SOLUTION
Hoist cylinder doesn't lift load or
won't move
l
Empty
a) Plugged inlet hose.
a) Unplug hose or replace
b)
Insufficient oil b) Check truck hydraulic system for correct
oil level in tank, defective pump or pump
drive, leaks in the lines or disconnected
control valve linkage. Repair or replace
as necessary.
l
Loaded
c) Bent or jammed plungers. c) Repair or replace as necessary.
AWARNING:
Extreme care should be used when working on a unit when the carriage
(with or without load) is in a raised position.
a) Plugged piston checkvalve-outer a) Unplug check valve or replace.
plunger may move.
b) Truck relief setting low. b) Raise truck relief setting to specified level.
Minimum: 2200 psi (150 bar)
Maximum: 2500 psi (173 bar)
c) Over capacity
C)
Reduce load to specified capacity
d) Mechanical bind due to bent plungers(s), d) Remove mechanical bind by replacing/
bad rollers and/or bad crosshead guides. freeing plungers and guides.
AWARNING: Extreme care should be used when working on a unit when the carriage
(with orwithout load) is in a raised position.
Mis-sequencing
l
Empty or light load
Inner Plunger up - 1 st
Outer Plunger up- 2nd
l
Loaded
Inner Plunger up - 1 st
Outer Plunger up- 2nd
Hoist cylinder drifts -
0 All plungers down
l
Inner plunger down
Outer plunger up
a) Bent plungers. a) Repair or replace as necessary.
AWARNING: Extreme care should be used when working on a unit when the carriage
(with orwithout load) is in a raised position.
a) Bent plungers.
b) Repair or replace as necessary.
A
WARNING: Extreme care should be used when working on a unit when the carriage
(with or without load) is in a raised position.
a) External leak in pressure line. a) Tighten or replace as necessary.
b) Truck valve defective-cycle to full lift b) Repair or replace truck valve.
height to verify.
c) External leaks at retainers. c) Replace all cylinder seals,
a) Piston checkvalve leaking. a) Replace check valve.
677736 Rev. 0
Continued
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