If the axle is bent, out-of-round, or shows signs
of wear, replace it. Check for worn roll pin holes. If these are damaged
or worn, replace the axle.
Bushings are designed to wear out sooner than the mating
parts. They are made of softer material and are expendable. It is recommended
that anytime the jack is torn down to a point where the bushings are
accessible, they be replaced. This will ensure longer life of the jack
and will reduce the amount of downtime. Bushings are very inexpensive
and it is cost effective to change them regularly.
If bushings are cracked, broken, egg shaped or worn
more than 1/16" from the original size replace them.
Remember: If the jack is already disassembled, replace
all accessible bushings.
Tip: Coating axles and bushings with anti-seize compound
before installation makes maintenance easier.
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Rollers and Load Roller Brackets
Load rollers - Load rollers should not have flat spots
or large pieces of metal imbedded in them (i.e. tacks, nails or metal
shavings). Any chips in the wheel that keep it from rolling smoothly
indicate the need for replacement. If the wheel has cracks, loose tread,
or does not turn freely, replace both wheels. Always change the wheels
in pairs to reduce uneven wear. New load rollers have an outside diameter
of 2 3/4" (PT55) or 3" (PT50). If the diameter is worn more
than 1/4" from normal size, replacement is necessary.
Load roller brackets - Inspect the brackets for cracks
or wear from prolonged rubbing on the floor. Check for out-of-round
axle holes and inspect the bushings closely (see Bushing Inspection).
If any of the above conditions exist, replace the brackets.
Tip: We recommend servicing one load roller assembly at a time, while
using the other assembly as a reference.
Load rollers - Remove the roll pin from the load roller
axle and drive out the load roller axle.
Load roller brackets - Remove the load roller assembly,
then the screw and nut which secures the pivot axle in place.
Drive out the pivot axle, pull the push rod away from the frame, and
pull the brackets off the push rod axle. (15 minutes)
Load roller brackets - Slide the brackets onto the
push rod axle in the tee clevis. Insert the pivot axle through the frame,
exit roller, sleeve and the brackets. Secure it with the screw and nut.
Install the load roller axle through the brackets and roller, and secure
the axle with its roll pin.
Load rollers - Place the wheel between the bracket
and install the axle through the bracket and load roller, then install
the roll pin. (10 minutes)
Wheels and Axle
Steer wheels should not have flat spots or large pieces of metal imbedded
in them (i.e. tacks, nails or metal shavings). Chips in the wheel, which
keep it from rolling smoothly, indicate the need for replacement. Steer
wheels should turn freely. They should not rub the bottom of the traverse.
If they do, check for the correct installation of the snap ring under
the traverse. New steer wheels are 8" in diameter. If the wheel
is worn more than 1/4" from the normal diameter, replacement is
Steer wheels - Turn the jack onto its side. Pull the
cotter pin out and slide the wheel off the axle. (10 minutes)
Steer wheel axle - Remove the steer wheels. Depending
on the configuration, remove the roll pin or back the set screw off
that secures the steer wheel axle in place. Some hydraulic units don't
use any fasteners to hold the steer wheel axle in place. (15 minutes)
Steer wheel axle - With the jack on its side, slide
the axle into the stem of the hydraulic unit and secure with its fastener
(if it has one), then install the steer wheels. (15 minutes)
Steer wheels - Slide the wheel onto the axle and secure
in place with the cotter pin. (10 minutes)
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There are few things that can be wrong with the traverse. Wear can occur
on the bearing shoulder or where the shoulder bolts attach to the lifting
link. If these areas are egg-shaped or out of round, replace the traverse.
Turn the jack onto its side so the weight is resting on the fork and
the jack stand. Remove steer wheel and axle assembly (see Steer Wheels
and Axle Removal). Remove the snap ring under the traverse on the stem
of the hydraulic unit. Carefully turn the jack upright. Remove the screw
that fastens the ram to the frame. Lift the frame off of the ram and
pull the hydraulic unit out of the traverse. Loosen the set screws that
secure the shoulder bolts in place, and remove the shoulder bolts and
the traverse. (20 minutes)
Attach the traverse to the lifting link with the shoulder bolts and
tighten the set screws. Position the thrust bearing on the traverse.
Slide the hydraulic unit into the traverse. Insert the top of the ram
into the A-Frame and secure it with the screw. Turn the jack over onto
its side and install the snap ring that holds the traverse in place
on the stem of the hydraulic unit. Install the steer wheel axle and
steer wheels (see Steer Wheels and Axle). (20 minutes)
When inspecting the push rods, look for broken or cracked welds, bends,
and out-of-round holes. If any of the above conditions exist, replace
the push rod. We suggest that you work on one side of the jack at one
time, so you can use the other side as a reference.
Turn the jack over so the undercarriage is facing up. Drive the roll
pin out of the pin connecting the lifting link to the push rod. Remove
the pin and unscrew the push rod from the tee clevis. It is helpful
to mark the adjustment of the tee clevis for proper installation. (10
Fully lower the pallet jack and turn it over so that the undercarriage
is facing up. Thread the push rod into the tee clevis to the point that
the holes of the push rod line up with the lifting link and insert the
pin that attaches the two parts. Drive in the roll pin to secure the
pin in place. To ensure the push rods are adjusted correctly, turn the
jack over to its normal operating position. Then raise the jack and
stand on the forks, facing the handle. While standing on the forks,
lower the jack and determine if both forks bottom-out at the same time.
If one reaches the floor before the other, adjustments are needed. You
can shorten the adjustment on the fork that hit second or lengthen the
adjustment on the fork that hit first. (15 minutes)
Check lifting link for out-of-round holes, cracks in welds, or bent
ears. If any of these conditions exist, replace the lifting link. Also,
look for worn bushings, missing shoulder bolts, missing lifting link
pins or the roll pins that fasten these parts to their mating parts.
Remove the screw in the top of the A-Frame that fastens the ram to the
jack. Remove the set screws and shoulder bolts that fasten the traverse
to the lifting link. Remove the pump, traverse and steer wheel assembly
as one unit. Turn the jack over so that the undercarriage is facing
up. Remove the pins that attach the push rod to the lifting link (see
Push Rod Removal). Remove the set screws that secure the lifting link
pins in place. The interior of the lifting link pins are threaded for
a 5/16”-24 bolt. Screw in a 5/16”-24 bolt into the lifting
link pin and pull the pin out using the bolt. The old style lifting
link uses one long shaft held by a bolt and nut at one end. Remove the
nut and bolt, punch the shaft through far enough to get a hand on it
and pull it free of the jack. (45 minutes)
Turn the jack over so that the undercarriage is facing up. Position
the lifting link into the frame so the holes line up with the holes
in the frame. Install the lifting link pins and set screws. Attach the
push rods (see Push Rods). Secure the traverse (with the pump and steer
wheels still attached), with the shoulder bolts and their set screws.
Fasten the top of the ram to the frame with the screw. (45 minutes)
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Removal and Installation
Inspect the handle for cracks and structural integrity. There should
be minimal side play in the handle bracket. Check for worn bushings.
If bushings are not replaced regularly, the handle
bracket holes can become worn. This may require complete handle bracket
replacement to prevent unnecessary wear on mating parts. Also, inspect
the handle pin and roller for flat areas and wear. If any of the above
parts are worn more than 1/16", replace them.
Foot Control Removal
Remove the bolts fastening the handle to the handle bracket and the
handle will slide out. If you need to remove the bracket, remove the
roll pin fastening the handle pin in place. Remove the handle pin so
the bracket can be removed. Be careful to retain the pump piston in
the hydraulic unit. (10 minutes)
Foot Control Installation
Place the handle bracket into position on the hydraulic unit. Insert
the handle pin and secure it with a roll pin. The handle can then be
inserted into the handle bracket and secured with the nuts and bolts.
Hand Control Removal
Remove the handle and handle bracket together. Remove the screw that
holds the handle pin in place and remove the handle pin. The handle
bracket assembly can now be removed. Be careful to keep the pump piston
in place when removing the handle assembly.
To remove the handle from the bracket, remove the nut fastening the
release lever to the bracket. Pull the release lever free from the control
rod. Remove the nuts and bolts holding the handle and bracket together,
and the handle will come free. (10 minutes)
Hand Control Installation
Attach the handle assembly to the brackets with the nuts and bolts.
Slide the release lever into the lower end of the control rod. Place
the handle assembly into position on the hydraulic unit. Insert the
handle pin through the hydraulic unit and handle assembly. Secure with
the screw. (15 minutes)
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Unit - Inspection
Inspect the outside of the pump for oil leaks. Test the unit, under
a load, to determine if there is a problem. This can be done by lifting
a heavy pallet and letting it stand for 15-20 minutes. Below are symptoms
and solutions to common hydraulic unit failures. If the following solutions
fail to correct the problem, send the unit to us. If the following solutions
fail to correct the problem, a complete rebuild of the malfunctioning
unit may be necessary. Please refer to our catalog for information about
ordering the appropriate seal kit, or take advantage of our hydraulic
unit exchange program.
Jack fails to lift load
• Air Lock in Pump - Place the control mechanism
in the release position, then pump handle rapidly 10-15 times. (5 minutes)
• Low Fluid Level (Foot or Hand Control) - With
the jack in a lowered position, remove filler plug. Using UNI-HO oil,
fill the reservoir until the oil is level with the fill plug hole. Bleed
the unit (see Air Lock in Pump). Replace the filler plug, creating a
snug fit. Do not over-tighten. (5 minutes)
• Hand Control Out of Adjustment - Pull the plastic
cover off the stud that the pedal plate rides on. Loosen the first nut
in order to adjust the second nut. Adjusting the second nut in or out
will affect how soon the hydraulic unit goes into release and neutral.
The pedal plate should be touching the valve pins. When the pedal plate
is pressing the valve pin farthest away from the pump piston, the unit
should be in neutral. When the pedal plate is pressing in the valve
pin nearest to the pump piston, the unit should be in release. (5 minutes)
• Foot Control Malfunctioning - Pull the plastic
cover off the stud that the foot pedal rides on. Loosen the first nut
to adjust the second nut. The foot pedal should have 3/4” of free
play before the release pin is engaged. The valve pins should be in
contact with the pedal in all positions. (5 minutes)
Jack fails to lower
• Look for any bent or damaged frame parts (lifting link, push
rod, etc.). Bent or damaged frame parts should be replaced.
• Foot or hand control is out of adjustment (see Hand Control
Out of Adjustment or Foot Control Malfunctioning).
• Debris blocking an oil channel in the hydraulic unit. Contact
us for our hydraulic core exchange program.
Jack lifts in short increments
• Lack of oil pressure - see Low Fluid Level
• Reservoir filler plug leaking - Replace the washer and filler
plug and replenish oil, if necessary (see Low Fluid Level).
One fork lifts, the other does not
Check for damage in the following areas
and their attached parts:
• Lifting link (lifting link pin and traverse shoulder pin)
• Load roller bracket (pivot axle)
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Unit Service Hints
• Tampering and abuse are two of the most common
problems. In most cases, minor repairs become major when inexperienced
people attempt to rebuild a hydraulic unit. If you come across a unit
that looks like it has been tampered with or modified, inspect the unit
carefully to be sure it can be rebuilt or call Generic Parts Service
for technical assistance.
• The ram is chromed and the pump piston polished
to a fine finish for maximum seal life and minimum oil leakage. If you
see these surfaces nicked or pitted, this will cause the unit to fail
in a short time. Replace any rusty or damaged parts that will cause
premature wear on their mating parts or the body of the hydrualic unit
• Use UNI-HO hydraulic oil.
Do not use automotive oil or hydraulic brake fluid.
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Pump the jack to its maximum height and turn the jack
onto its side. Remove the steer wheels and axle (see Steer Wheels and
Axle Removal) and the snap ring under the traverse on the stem of the
hydraulic unit. Turn the jack upright; be careful no to damage the stem
of the hydraulic unit while lowering. Remove the screw that fastens
the top of the ram to the frame. Lift the frame off of the ram, tip
the handle and hydraulic unit away from the frame, and rest both pieces
on the ground. Remove the ball on top of the ram and pull the hydraulic
unit out of the traverse. Remove the handle and handle bracket if necessary
(see Handle Removal). (45 minutes)
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Slide the stem of the hydraulic unit into the traverse
with the traverse bearing already in place on the stem. Insert the ram
into the A-Frame with the ball positioned on the top of the ram and
secure the ram to the A-Frame with the screw. Carefully turn the jack
onto its side, keeping the hydraulic unit in the traverse and frame.
Attach the snap ring to the stem of the hydraulic unit under the traverse.
Install the steer wheel assembly (see Steer Wheel and Axle Installation)
and the handle, if necessary (see Handle Installation). Bleed the hydraulic
unit (see Air Lock and Pump). (45 minutes)
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