8
Maintenance
IMPORTANT:
Repairs and seal ring replacements
should be performed only by qualified personnel.
Also, certain procedures may require specialized
tools. You can locate the nearest authorized JET
Service Center on our website: www.jettools.com.
Numbers in parentheses refer to index numbers in
the parts breakdowns, pages 10-12.
O-Ring and Seal Replacement for
Ram Piston and Plunger Piston
1. Raise the pallet truck to maximum height by
pumping handle.
2. Unscrew the set screw (#69) to release the
ram shaft from the top of the frame.
3. Turn the pallet truck on its side. Remove the
wheels and wheel shaft. Remove the C-clip
(#25). This will free the pump and handle
assembly from the main truck body.
4. Turn the pallet truck upright. Remove drain
plug (see Figure 7) and empty the oil into a
suitable container. Pump handle until all oil
has drained.
5. Pull out piston rod (#57). If plunger piston
(#61) is to be pulled out, remove handle
assembly to access.
6. Remove all O-Rings & Seals.
7. Insert new O-Ring or Seal one at a time
making sure to replace with the same size that
was removed.
8. Re-assemble.
9. Refill oil to correct level (80% capacity or
approximately 2 inches deep in reservoir), and
install oil fill plug.
O-Ring and Seal Replacement for
Valve Cartridge
1. Remove drain plug (see Figure 7), and empty
the oil into a suitable container. Pump handle
until all oil has drained.
2. Tap out spring pin (#19).
3. Remove the relief cam (#18).
4. Unscrew the valve cartridge (#41).
5. Remove all O-Rings & Seals.
6. Insert new O-Ring or Seal one at a time
making sure to replace with the same size that
was removed.
7. Re-assemble the valve cartridge, and install
relief cam with spring pin.
8. Refill oil to correct level (80% capacity or
approximately 2 inches deep in reservoir), and
install oil fill plug.
Cleaning the Release Valve
(Bleeding the Pump)
Over time the release valve assembly may become
clogged with debris. To clean the release valve:
1. Pump handle quickly raising pallet truck to full
extent. While continuing pump action, pull
lever to down position.
2. When forks reach total down position, valve is
flushed. Repeat if necessary.
Adjusting Relief Cam
1. Place handle lever in the neutral position.
2. Loosen #20 hex nut.
3. Adjust #21 socket set screw while pumping the
handle.
4. The cam is properly adjusted when pumping
the handle in the neutral position causes no
movement.
5. Re-tighten hex nut (#20) to secure the setting.
