ED EPT20-15EHJ User manual

Service Manual
EPT20-15EHJ
Semi-electric Pallet Truck
MANUAL NO. SM1121 01.16

CONTENTS
Table of contents
1.LOAD WHEELS...............................................................................1
1.1 Disassembly and Assembly.......................................................1
2.DRIVE UNIT....................................................................................2
2.1 Disassembly and Assembly.......................................................2
3. TILLERHEAD .................................................................................4
4. HYDRAULIC SYSTEM...................................................................7
4.1Disassembly and Assembly........................................................7
4.2 Commissioning..........................................................................8
4.3 General Failures and Troubleshooting......................................9
4.4 Oil Seal Replacement..............................................................12
4.5 Other Issues............................................................................15
5. ELECTRICAL ...............................................................................17
5.1 Disassembly and Assembly.....................................................17
5.2 Electrical Schematic Diagram..................................................19
5.3 Power Cables..........................................................................20
5.4. Controller Troubleshooting .....................................................21
5.4.1. Fault Detection .................................................................21
5.4.2. Hand Held Programmer (Optional)...................................21
5.4.3. Fault Recording................................................................21
5.4.4. General Checkout.............................................................21
5.4.5. Diagnostic History.............................................................23
5.4.6. Test the Fault Detection Circuitry......................................23
5.4.7. Programmable Parameters ..............................................23
5.4.8. Diagnostics and Troubleshooting.....................................24
5.4.8.1. LED Diagnostics.........................................................24
5.4.9. Programmer Diagnostics...............................................24

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LOAD WHEELS
1.LOAD WHEELS
Place hardwood block under the Frame as shown in
Figure 01101.Remove the riser pivot shaft (index 2)
after extracting roll pin (index 1).
Remove the riser pivot shaft (index 4) after
extracting roll pin (index 3) as shown in Figure
01102.Then the wheel bracket assembly (index 5)
can be replace.
If the load wheel (index 9) is only replaced, the
riser pivot shaft (index 7) will have to be removed
after extracting roll pin (index 6) as shown in Figure
01103.Remove the bearings (index 8) and change
the load wheel (index 9).
CAUTION
In order to avoid scratching the surface of vehicle,put
a piece of rubber mat on the hardwood block.
1.1 Disassembly and Assembly

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DRIVE UNIT
2.DRIVE UNIT
Place hardwood blocks under the Frame as shown
in Figure 01201.Make the drive wheel hang in the air
Unfasten the four screws (index 1, Figure 01202) by
using a wrench and remove the upper cover (index 3)
and the lower cover (index 2) .
Dismantle the motor cable box (index 4) and remove
the two cables (index 5).Unscrew the three screws
(index 6) and take down the brake (index 7).Unfasten
the eight screws (index 8) and remove the gear box
cover (index 9) and the gears (index 10) .Note the
number and position for reference at assembly.Then
knock out the assembly (index 12) after unscrewing
the five screws (index 11).Refer to Figure 01203.
CAUTION
Put the hardwood block as neer the drive wheel as
possible.
2.1 Disassembly and Assembly

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DRIVE UNIT
Refer to Figure 01204. Knock out the motor (index
13)and pick out the oil seal (index 14).After the six
screws (index 15) have been removed, knock out
the gear ring (index 16) and the bearings (index 17)
.Then the drive wheel can be changed.
Change the brushes
If the brushes (index 7) must be repalced,the motor
will have to be dismantled.
Unfasten the three screws (index 1),Open the
moter.Remove the four screws (index 5) and pick
out the brush holder (index 6).Then the brushes
(index 7) can be replaced.Refer to Figure 01205.

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TILLERHEAD
3. TILLERHEAD
1. IMPORTANT-SAFETY
Verify that spring safety pin is in place. The pin
should be well rested in the holes situated on each
side of the pump housing. If the safety pin is not
rested properly in one of the holes, put pressure on
the spring using a “C” clamp pushing down on the
pump stem. Once pressure is relieved on the pin,
reinsert properly and remove clamp slowly.
2.
Insert handle pin into corresponding holes and ,
drive in one cotter pin on one side only(see arrow 2).
Note: Insert handle pin without the
handle and verify that the
center hole is facing you
(see arrow 1).
3. IMPORTANT-CHAIN
Before this step, make sure to feed the chain on the
outside of the piston stem roller (see arrow 1).If left
in its proper position, it will not be possible to insert
the handle pin and chain, breakage may occur.
Align handle holes with pump housing holes and
push through handle pin(see arrow 2).
Figure 01301
Figure 01302
12
Figure 01303
1
2
3.1 Disassembly and Assembly

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TILLERHEAD
4.
Make sure that handle pin is completely through
the handle and resting on the other side.
5.
Feed the chain and nut first back inside the
handle through the handle pin's center hole.
IMPORTANT-TIP
Release the up/down lever to its lowest position
to make the process easier.
Once the chain is in the proper position, check
to see that it moves freely and that it is not
obstructed.
6.
Use both hands, push on the valve cam to raise
the hook inside the housing and feed the end of
the chain in the cam.
7.
Pull down on the handle to release the tension
on the safety pin. CAREFULLY remove the
safety pin.
Figure 01304
Figure 01305
Figure 01306
Figure 01307

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TILLERHEAD
8.
Connect the both electrical plugs.
9. IMPORTANT-FINAL CHECK
Test all the features of the semi-electric pallet
truck before this step. The handle should be
pumped with full strokes to prime and eliminate
air in the system.
The up/down lever should be checked at the
handle’s lowest position for this puts the most
tension on the chain. Once the
pallet truck is adjusted properly and is
performing well, drive in the second cotter pin.
10.
Tie the wire harness with a tie wrap(see arrow 1)
together .
Figure 01308
Figure 01309
Figure 01310
1

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HYDRAULIC SYSTEM
4. HYDRAULIC SYSTEM
Remove the handle (index 1) and the controller
(index 2).Remove the hydraulic assembly by
unscrewing the screw (index 3) and the four
screws (index 4).Place hardwood blocks under
the Frame as shown in Figure 01401.
The filler of hydraulic assembly is as shown in
Figure 01402.
Refer to Figure 01403. Change the lift capacity
by adjusting the position of the screw (index 2)
which is in the relief valve (index 1).
Screwing Inward = bigger
Screwing outward = smaller
The seal kit of hydraulic assembly includes
index 5,6,7,8&9.Pick out the piston rod (index 3)
and the pressure bar (index 4).Then the seals
are removed by using a hooked tool (index 10).
CAUTION
Put the hardwood block as neer the drive
wheel as possible.
CAUTION
It is filled with the 32# hydraulic oil.
4.1Disassembly and Assembly

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HYDRAULIC SYSTEM
4.2 Commissioning
After the handle is installed to the new vehicle, or
the vehicle has been used for more than 6 months,
further commissioning should be conducted to the
hydraulic pump, make sure that the hydraulic pump
is always working in the best condition. Gear lever
on the handle is associated with the screws on the
lever plate.
1. When the gear lever is at Gear 1, the vehicle is
in the state of lifting, turn the handle at this time,
the vehicle will be lifting.
2. When the gear lever is in the middle, Gear 2, the
vehicle is in the state of traveling, turn the handle
at this time, the vehicle won't be lifting or lowering,
this working condition is forward or reverse state.
3. When the gear lever is flipped to higher position,
Gear 3, the vehicle will be in the lowering state.
Operate the vehicle slowly when lifting hea-
vy load, do not rapidly flip the gear lever,
otherwise may damage the vehicle or the
loads!
4. After the handle is installed properly, follow the
steps described below for commissioning, the
methods are as follows:
The position of the screws underneath the lever
plate will decide if the working condition of gear
lever is normal:
Turn the handle, but the vehicle cannot lift, slightly
turn the screw counterclockwise and try turning
the handle until the vehicle can lift properly;
If there is no middle gear or the vehicle is lowering
too slowly, slightly turn the screw clockwise and
try turning the handle again until it can shift proper-
ly among the three gears, namely: middle, lifting,
lowering;
Hexagon nut at the screw is for the purpose of
locking, loosen it prior to adjustment and tighten it
after the adjustment is completed.
iThis step may be repeated several times so as
to complete this work, if necessary, until each
gear is functioning properly.

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5. Relieve Valve Commissioning
If the vehicle can lift light load, but cannot lift rated
load, such case may be caused by the relief valve
being opened in advance, follow the steps below
for commissioning:
Firstly, remove the external screw plug of the relief
valve, and then adjust it with screwdriver;
Turn it clockwise to increase opening load of relief
valve;
Turn it counterclockwise to decrease the opening
load of relief valve.
Install the screw plug back in place after the com-
missioning is completed.
DO NOT turn too much during adjustment, the
angle is recommended to be less than 15° at
one time.
1. The vehicle cannot lift?
Cause 1 Due to transportation, long time storage or inversion, it is likely to be air entering into
the hydraulic system of the pump.
Troubleshooting:
Flip the gear lever on the handle to lower-
ing position and fully turn the handle for
several times to discharge the air within
the hydraulic system of the pump, repeat
for several times, if necessary.
Cause 2 Unloading valve abnormalities, unloading valve stem not at normal operating
position.
Troubleshooting:
Check if the commissioning is in place.
Relief valve must not be closed completely,
otherwise, once the valve is overloaded, the
vehicle will be damaged!
4.3 General Failures and Troubleshooting
HYDRAULIC SYSTEM

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2. The vehicle cannot lift to maximum height?
Cause It is likely to be insufficient hydraulic oil.
Troubleshooting:
Refill hydraulic oil.
Different brands of hydraulic oils, and oils
from different vendors cannot be mixed
together! Otherwise may accelerate the
premature deterioration and failure of
hydraulic oil!
Cause 3 Check if the unloading valve stem is
blocked.
Troubleshooting:
Push the unloading valve stem in the
direction of the arrow as shown in the
figure, if the stem can automatically reset,
then it indicates that the fault is due to
insufficient commissioning, the fault can
be fixed through re-commissioning.
If the valve stem can only be pushed
forward, but cannot be pulled backward,
and cannot automatically reset, the stem
seems to be blocked, then the valve stem
and related parts need to be replaced.
Sometimes, by applying lubricants on the
surface of valve stem can also make it
reset.
Cause 4
The hydraulic oil viscosity changes due
to different ambient temperature or long
time storage, as well as alpine region, the
hydraulic oil may freeze or may become
diluted at tropical region, long time use of
hydraulic oil with no replacement can also
lead to qualitative change, thickening or
drying of the oil, and so on.
Troubleshooting:
Needs to replace with new hydraulic oil.
i
HYDRAULIC SYSTEM

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3. The vehicle can lift but cannot retain, by turn-
ing the handle, the vehicle can lift, or although
the vehicle can lift, but then automatically
lower?
Cause 1 Valve blocked by debris.
Troubleshooting:
Remove all the parts within the valve,
clean them up and re-install, the fault can
then be fixed.
Seals need to be replaced when necess-
ary.
1. Valves are precision parts, apart from
the seals, no parts shall be replaced or
swapped between two vehicles, otherwise
may need a technician with certain skills to
fix!
2. An appropriate amount of hydraulic oil
needs to be refilled depending on the loss
of hydraulic oil! Warning! DO NOT attempt
this repair operation without proper
training!
4. The vehicle can lift but cannot lower?
Cause 1 Piston rod bent or bonded with cylinder
block.
Cause 2 May be caused by other parts on the
vehicle.
Cause 3 May be caused by the vehicle getting rusty
or blocked by foreign bodies.
Troubleshooting:
Check all the related parts of the entire
vehicle for abnormalities, remove the
foreign objects on other parts, rectify and
replace the damaged or deformed parts.
5. The vehicle cannot lower to bottom?
Cause 1 Excessive hydraulic oil.
Troubleshooting:
Drain the excessive hydraulic oil.
HYDRAULIC SYSTEM

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5. The vehicle cannot lower to bottom?
Cause 2 Parts deformation of parts.
Troubleshooting:
Check other parts of the vehicle, remove
foreign objects and replace the parts with
deformation.
6. Oil leakage?
Cause 1 Damaged seals.
Troubleshooting:
Replace the damaged seals.
Cause 2 Loose parts.
Troubleshooting:
Carry out the troubleshooting again and
tighten the loose parts.
Cause 3 Sealing surface of parts scratched.
Troubleshooting:
Replace the damaged parts and related
seals.
4.4 Oil Seal Replacement
1. Replace the main oil seal of piston pump.
Failure symptom: oil leakage at piston pump.
Cause: Damaged pump oil seals.
Troubleshooting: Replace the pump seals.
Replacement procedure: Remove the piston pump
element, big spring and other parts, then get the oil
seal removal tools A, B and C ready, and replace the
oil seals with these tools.
iThe pump oil seal groove is of closed structure,
extra care shall be taken upon replacement.
HYDRAULIC SYSTEM

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Removal of pump seals can roughly be divided into
four steps, as shown below:
1.Use tool A, apply a force in the direction of the
arrow, squeeze the tool between the oil seal and
the engaging surface of the groove;
2. Apply a force in the direction as shown in the fig-
ure, initially thrust the oil seal out of the groove
with tool, if necessary, stab the oil seal with tool C
and then thrust it;
3. Apply a force in the direction of the arrow as sho-
wn in the figure, thrust the oil seal completely out
of the groove;
4. Go on thrusting tool A and turn it for 180°, draw
and prick to remove the oil seal finally.
Installation of pump seals can roughly be divided
into four steps, as shown below:
1. Press the oil seal into the pump hole with tool B;
2. Partly draw the oil seal into the groove as shown
in the figure;
3. Progressively draw the oil seal into the groove as
shown in the figure;
HYDRAULIC SYSTEM

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4. Adjust the oil seal in the groove to rectify it in place.
The tools shall be with no sharp edges and
corners, otherwise may easily damage the oil
seal!
DO NOT attempt this repair operation without
proper training!
2. Replace oil seals of big cylinder.
Failure symptom 1 : After the big piston rod is lifted,
it is lowered rapidly.
Failure symptom 2 : After the big piston rod is lifted
under no load of light load, the-
re is no obvious sign of lower-
ing, but it is lowered rapidly
under heavy load.
Cause: Damaged big piston seal.
Troubleshooting: Replace the big piston seal.
iThe big piston seal is of open structure.
Removal of big piston seal can roughly be divided
into three steps, as shown below:
Replacement procedure:
1. Remove the big piston rod first, as shown in Figure
①, it can be directly pulled out;
2. Loosen the guide bushing with a wrench, as sho-
wn in Figure ②until it is thoroughly removed;
3. Remove the big piston seal from the guide bush-
ing, as shown in Figure ③.
HYDRAULIC SYSTEM

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REV. 03/2015
4. Install the big piston seal and other parts in rever-
se order of the removal procedure.
iThe removal of big piston seal can be carried
out with tool A, B and C, and the method is the
same as that for pump seal, if so, the guide
bushing does not need to be loosened.
4.5 Other Issues
1.Hydraulic oil: anti-wear hydraulic oil ISO-32 is used
for general regions, it is recommended to use ISO
VG 15 hydraulic oil at extremely cold areas or cold
storage, the allowed oil volume within the pump is:
250~280mL.
Neither too much nor too little oil can make
the pump work properly, you can also visually
observe until the oil overflows from the filling
hole.
2. Daily inspection and maintenance are essential,
the appearance of the pump should always be
cleaned up to prevent big and small piston rods
from being scratched by foreign objects; lower the
vehicle to the bottom when idling, unload the loads
from the vehicle, the loads must not be placed on
the vehicle for a long time.
3. The commissioning shall be made every 6 mon-
ths, so that the control stem is always in the cor-
rect position.
4. Prior to the pump inspection, make sure the veh-
icle is lowered to bottom, otherwise, once the parts
on the pump are loosened, the high pressure liquid
inside can be ejected, and may lead to hazards.
5. Upon inspection, including prior to the inspection,
clean up the stains on the appearance first, and
clean up each part from time to time during the
inspection and cover all the exposed holes proper-
ly to prevent dirt from entering the system; welding
or grinding may generate dust, such operations
shall be prohibited at the site of pump repair.
6. After the repair or replacement of parts, the
parts shall be cleaned up first, make sure the
parts are thoroughly clean and then install again.
HYDRAULIC SYSTEM

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7. If the seals within the pump need to be replaced,
smooth tools must be used, any sharp tool can
cause damages to the seals, resulting in failure of
hydraulic functions.
8. Upon removal or demolition, pay attention to the
order and direction of the removal, the parts re-
moved must be kept properly to avoid the occurr-
ence of loss, scratches and deformation, all parts
must be kept clean after the repair and before the
installation.
9. The operator is required to apply even force when
tightening the parts during installation, otherwise
may lead to damage to parts or deformation of
valve, blocked spool or oil leakage at joining parts,
and other problems.
10.The oil in the tank shall be refilled or replaced
upon inspection, and the viscosity of the oil must
comply with the relevant requirements, the new oil
must be filtered before use to ensure it is clean
and free of impurities.
11. After the inspection, double check the parts that
has been repaired, make sure there is no problem,
then adjust the system in accordance with relevant
requirements, observe the parts for abnormalities,
only after having confirmed that everything is
normal, can the part be put into operation again.
12.DO NOT attempt to the repair operations without
proper training!
13. Discard:
- Demolish the product first, drain the hydraulic oil,
and classify the parts by metal parts and rubber
parts;
- The waste hydraulic oils shall be collected and
transported to used oil recycling sites or burned in
accordance with national safety standards;
- More than 99% of the parts in this product are
made of metal, which can be handed to scrap
metal recycling agent for disposal;
- Very little rubber parts can also be used as renew-
able raw materials and sent to the local recycling
agent for disposal.
HYDRAULIC SYSTEM

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ELECTRICAL
5. ELECTRICAL
Change the batteries
Lift the forks by moving the handle (index 1)
up and down to the highest.Rotate the handle
a few degrees to the left or right as shown in
Figure 01501.
Remove the two screws (index 2) and take out
the battery cover (index 4).
After the wire harness and cables have been
removed from the batteries carefully, the
batteries can be took out.
Change the charger
Lift the forks by moving the handle (index 1)
up and down to the highest.Rotate the handle
a few degrees to the left as shown in Figure
01502.
Remove the two screws (index 2) and take out
the battery cover (index 4).Then remove the
wire harness from the battery.
Remove the battery connector (index 5) in order
to replace the charger easily.
Refer to Figure 01503.Unscrew the three lock
nuts (index 6) and remove the bracket (index 7)
from the front frame.
Disconnect the LED lamp and charger cable
from the charger. Unfasten the screws (index
10) and lock nuts (index 11).Then the charger
can be replaced.
5.1 Disassembly and Assembly