
Rev. 2/11/2021
CART-LP, MANUAL
Copyright 2021 Vestil Manufacturing Co.
Page
12
of
14
TROUBLESHOOTING
Use this guide in conjunction with the Troubleshooting section of your
Solutions in
italics
are found in the MPU-DC manual.
for assistance with issues that
do not appear in this guide.
Issue
Explanation
Solution
1. Deck does not rise when UP
button pressed, but pump is
running.
a. Voltage at motor terminals too low to run
pump.
b. Hydraulic hose leaking.
c. Fluid level in hydraulic reservoir too low.
d. Load exceeds capacity/max. rated load
limit (relief valve opening).
e. Clogged suction filter.
f. Suction line leaking or loose fittings.
g. Clogged filler/breather cap on tank.
h. Lowering valve energized by faulty
wiring or stuck open.
i. Hydraulic pump malfunctioning.
j. Low battery charge.
a.
Measure voltage at motor terminals (or
as close to terminals as possible) while
pump runs under load. If voltage is
adequate, check wiring
.
b. Correct as appropriate.
c.
Add fluid.
The system uses HO150
hydraulic fluid. Replace the hydraulic
fluid with an anti-wear hydraulic fluid of
viscosity grade of 150 SUS at 100°F
(ISO 32 @ 40°C) such as AW-32 or
Dexron transmission fluid
.
d.
Reduce weight applied to deck. DO
NOT change relief valve setting!!
e.
Remove filter and clean it
.
f.
Inspect all fittings for proper fit
.
g.
Remove and clean
.
h.
Remove lowering valve and clean
.
i.
Disconnect hydraulic line from cylinder.
Put free end of hose in large container
and cycle the pump. If no oil output,
check pump-motor coupling. Contact
factory to order replacement pump, if
necessary
.
j.
Recharge battery
.
2. Forks rise too slowly
k. Debris stuck in lowering solenoid valve
causing portion of fluid to flow to
reservoir.
l. Debris clogging suction filter or breather
cap.
m. Pinched hose.
n. Low motor voltage.
o. Too much weight applied to deck.
p. Pump malfunctioning.
q. Insufficient battery charge.
k.
Lower deck. Remove solenoid valve
and clean
.
l.
Correct as appropriate (see also
solutions “f” and ‘h”)
.
m. Repair the hose.
n.
Measure voltage at motor terminals (or
as close to terminals as possible) while
pump runs under load. If voltage is
adequate, check wiring.
o. R
educe weight applied to deck. DO
NOT change relief valve setting!!
p.
Disconnect hydraulic line from cylinder.
Put free end of hose in large container
and cycle the pump. If no oil output,
check pump-motor coupling. Contact
factory to order replacement pump, if
necessary
.
q.
Recharge battery
.
3. Motor labors or is really hot
r. Low voltage.
s. Incorrect wiring.
t. Oil starvation causing pump to bind.
High heat produced. Pump might be
permanently damaged.
u. Binding cylinders.
v. Insufficient battery charge.
r. See solution a.
s.
Confirm that one leg of motor line not
connected to ground
.
t. See d, f, g, h, and i.
u. Contact technical service.
v.
Recharge battery
.
4. Deck rises in jerks or support
of the deck feels spongy.
w. Fluid starvation.
x. Air trapped in cylinder(s).
w. See solutions d, f, g, I.
x. See Bleeding air from hydraulic system.
5. Deck lowers too slowly when
loaded.
y. Filter of lowering solenoid valve
clogged.
z. Pinched hydraulic hose.
aa. Debris in flow control valve.
y.
Remove lowering solenoid. Clean filter
.
z. Repair hose.
aa.
Remove and clean flow control valve
.