D4OPTRS 18 2019
TROUBLESHOOTER’S GUIDE
(continued)
PROBLEM
Hopper will not raise
CAUSE
Control valve coil not
energizing
Bad coil in control valve
bank
Low hydraulic system
pressure
Blocked hydraulic line in
one or both lift cylinders
Cylinder seal leak
SOLUTION
Check hydraulic system fuse;
check wiring to see that it is
attached to control valve coil. use
test light to see if wire is getting
electrical current; manually shift
control valve by pressing in
override buttons provided on end
of tube assemblies. If valve will
not manually shift, replace valve
segment. Refer to valve Drawing
M01021.
If hopper raises when control
valve is manually shifted (auxiliary
engine will be running) remove coil
from another control valve; insert
in place of suspected bad coil. If
valve operates, replace bad coil. If
valve fails to operate, disassemble
and check for foreign material.
If hopper does not raise when
manual overrides are depressed,
install pressure test gauge on
test port at pump. Refer to Page
I-6. Test system pressure by
lowering pickup head to ground;
after it is fully lowered, continue
to hold toggle switch in DOWN
position and read pressure gauge.
Reading should be 1500 PSI
(103.5 Bar). If less, increase
system pressure. If pressure
reading is 1500 PSI (103.5 Bar),
try to raise hopper and observe
reading; if 1500 PSI (103.5 Bar),
hopper is overloaded.
If hopper is not overloaded, then
hydraulic lines to lift cylinders
may be plugged; check for foreign
material in lines.
Check cylinder for internally
ruptured seals. Remove cylinder
from sweeper and disassemble.
Refer to section pertaining to
particular cylinder in question.
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