Big Joe PDBB-20-T12, Operation, Maintenance, Repair Parts List

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901357 4-1
SECTION 4
TROUBLESHOOTING
4-1. GENERAL
Table 4-1 serves as a guide to determine possible
causes of trouble. The table is divided into five main
categories: Truck Dead: Trouble With Travel: Trouble
With Braking: Trouble With Lifting Or Lowering, and
Miscellaneous malfunctions. Refer to electrical wiring
diagram (
Figure 4-2 or Figure 4-5 ) as a supplement to
the troubleshooting chart or when tracing an electri-
cal circuit.
Table 4-1 Troubleshooting Chart
MALFUNCTION PROBABLE CAUSE CORRECTIVE ACTION
TRUCK DEAD
Truck will not run nor will lift sys-
tem operate.
a. 120 Amp fuse blown. Check fuse and replace if defec-
tive.
b. Battery dead or disconnected. Check battery quick-disconnect
plug and check battery voltage.
c. Keyswitch defective. Bypass keyswitch to determine if it
is malfunctioning.
d. 15 amp control circuit fuse
blown.
Check fuse and replace if defec-
tive.
e. Defective wiring. Check for open circuit. Repair as
required.
TROUBLE WITH TRAVEL
Defective transistor controller. Refer to Paragraph 4-3.
TROUBLE WITH LIFTING OR
LOWERING
Check hydraulic oil level. Before
further troubleshooting, fill
hydraulic reservoir so that oil is
to "FULL" mark on dip stick.
Tighten all electrical connec-
tions.
Oil sprays or flows from the top of
the lift cylinder.
Defective packing in lift cylinder or
too much oil in reservoir.
Overhaul lift cylinder and install
new packing, seal, and wiper
ring.
Oil foaming from vent cap on
hydraulic reservoir.
Leak in suction line between the
pump and the reservoir or oil too
high.
Check oil filter. Replace if neces-
sary. Tighten fittings. Inspect line
and replace if necessary.
Oil splashes out of vent when low-
ering platform.
Oil level too high. Drain, then refill reservoir to
"FULL" mark on dip stick.
Squealing sounds when lifting
platform.
a. Oil level too low. Add oil to reservoir.
b. Dry channels in mast. Apply grease.
c. Defective mast or platform bear-
ing.
Replace bearing.
Platform does not lift to top. Pump
motor runs.
a. Oil level too low. Add oil to reservoir.
b. Load larger than capacity. Refer to nameplate on side of
mast for maximum load capacity.
c. Batteries need charging. Recharge.