40
Pub. 1147 - Rev. 7 SEPTEMBER 2004
Mechanical Dock Leveler Hydraulic Conversion
Problem
Probable Cause
Remedy
2. Platform does not raise (motor running) c. Hydraulic fluid level is low.
c.Check oil level in tank.
-Continued.
Refill if there is less than 3-1/2" of
oil in the tank when the unit is held
open with the SAFE-T-STRUT™. Do
not exceed maximum oil level
indicated by the “Oil Level” decal on
the reservoir (approximately 3-1/2"
depth).
d. System leak.
d.Check hoses, fittings, valves and
power unit for leaks.
e. The motor voltage is not correct.
e.Compare customer power supply to
motor requirements.
Compare customer power supply to
control box ratings.
f. Weight on platform.
f. Remove weight.
g. Shuttle valve is not adjusted properly.
g.Readjust shuttle valve.
h. Adjustable system relief valve pressure h.Readjust until the relief pressure is
is set too low.
1200 psi.
i. Debris in the hydraulic system.
i.Drain the oil from the power unit,
hoses and cylinders and replace with
fresh oil. Verify that the suction filter in
the tank is not clogged.
j. Platform cylinder failure.
j. Replace platform cylinder.
3. Leveler runs continuously when
a. ARTD cam is out of adjustment or
a. Readjust ARTD cam.
power is turned on.
damaged.
b. The ARTD system has failed.
b.Verify that ARTD and restrictor limit
switches are functional. Type 2 Control
Box – Verify that the limit switches are
wired to terminals 3 and 4. Verify that
ARTD actuator assembly is functional.
c. The pushbutton and or contact block
c.Type 1 Control Box – Replace switch
does not function properly.
and/or pushbutton operator.
Type 2 Control Box – Replace
pushbutton and/or contact block.
d. The solid-state motor controller has
d.Type 1 Control Box – Not applicable.
had an internal failure.
Type 2 Control Box – Replace solid-
state motor controller.
4. Lip extends slowly and/or does not
a. Debris on lip hinge.
a.Remove dirt, debris and corrosion from
fully extend.
the lip hinge spools.
b. Lack of lubrication.
b.Without grease fittings – Lubricate the
hinge spools with SAE30 oil.
With grease fittings – Lubricate the
hinge spools with moly based grease.
W h e n c h e c k i n g f o r a h y d r a u l i c s y s t e m
l e a k , f i r s t l o o k f o r t h e w e t h o s e s o r
f i t t i n g s w i t h o u t t h e p o w e r u n i t r u n n i n g .
O n c e t h e s u s p e c t e d l e a k h a s b e e n
l o c a t e d , h a v e a n a s s i s t a n t p o w e r - u p
t h e p u m p . M O V E A P I E C E O F C A R D -
B O A R D A R O U N D T H E S U S P E C T E D
LEAK TO LOCATE THE FAULTY PART.
DO NOT USE YOUR HAND. MAKE
S U R E T O K E E P H A N D S , A R M S A N D
FACE AWAY FROM THE AREA OF THE
S U S P E C T E D L E A K . H i g h p r e s s u r e
h y d r a u l i c f l u i d c a n b e a n i n v i s i b l e
s p r a y t h a t w i l l p e n e t r a t e f l e s h .
WARNING