8
Hydraulic System Troubleshooting Guide
(For additional information, contact the factory)
****
INSTALL MAINTENANCE SAFETY BLOCKS
OR DEPLOY MAINTENANCE PROPS BEFORE BEGINNING MAINTENANCE OPERATIONS
****
Observation
Possible Cause
Remedy
1.) Pump runs but table does not rise
2.) Table rises slowly.
3.) Motor labors or is ex
trem
ely hot.
4.) "Spongy" or "Jerky" table operation. Do not
confuse spongy operation with small surges caused
by
foreign material on table wheel roller plate.
5.) Table lowers too slowly when loaded.
a. Hose or hydraulic line is leaking.
b. Fluid level in reservoir is low.
c. Load exceeds capacity requirements. Relief Valve is
bypassing the fluid back into the reservoir.
d. Suction filter is clogged, starving pump.
e. Suction line may be leaking air, due to loose fittings.
f.
Filler/Breather cap on tank might be clogged.
g.
Lowering solenoid
valve
might be
energized
by
faulty
wiring or
might be
stuck
open.
h. Hydraulic pump may be inoperative.
a. Foreign material stuck in lowering solenoid, causing
some fluid to bypass back into tank.
b. Foreign material clogging suction filter, breather cap,
or a pinched hose.
c
. Table overloaded.
e. Pump is inoperative.
a. Oil starvation causes pump to bind. High internal
heat is developed. If this occurs, pump may be
permanently damaged.
b. Binding cylinders.
a. Fluid starvation.
b. Air in system.
a. Down Valve filter clogged.
b. Pinched tube or hose.
c. Foreign material in flow control valve.
d. Binding cylinders
e. Foreign material in velocity fuse.
a
. Correct as necessary.
b
.
Add fluid. Refer p. 10, parts B1 and C for proper fluid
level and type.
c
. DO NOT CHANGE RELIEF VALVE SETTING.
Instead, reduce the load to rated capacity.
d
. Remove and clean.
e
. Inspect all fittings for proper fit.
f
. Remove and clean.
g
.
Remove solenoid valve. Check and clean. (Refer to
p. 3).
h
. Disconnect hydraulic line at power unit. Put pressure
line in a large container and cycle pump. If no output,
check the pump motor coupline, which may be
defective, and correct as necessary. If pump is worn,
consult factory for replacement parts service.
a. Lower the platform. Remove the solenoid valve and
clean. (Refer to Hydraulic Section of Owner's Manual).
b. Correct as necessary. (See also
Remedies
1(
d
)
& 1
(
f
).
c
.
See Remedy 1(c).
e.
See Remedy 1(h).
a. See 1(
b
), (
d
), (
e
), (
f
), (
h
).
b. Align cylinders correctly.
a.
See 1(b), (d), (e), (h).
b.
Bleed air from the hydraulic system. Unload the table. Install
maintenance props and lower the deck until it is supported
by the props; then hold a rag over the bleeder valve (it
looks like a grease zirk) and open the valve by
approximately 1/2 turn with a 1/4 in. wrench
.
Oil and air will
sputter from the valve. Once no more air is observed. close
the valve.
a. Remove solenoid valve and clean filter.
b. Correct as necessary. (In case of pipe, check for
obstruction in line.)
c. Remove and clean Flow Control Valve. (Refer to
Hydraulic Section of Owner's Manual).
d. Align cylinders correctly.
e. Remove and clean velocity fuse. (Refer to Hydraulic
Section of Owner's Manual.)
