1. Actuate the chair’s base and chair’s back to complete up position. Raise the toe board and secure using tilt roller assembly. Remove the cover from the pump housing along with the upper and lower lift arm covers. (see Figure 1)
2. Remove the hitch pin and collar (see Figure 2). NOTE: Model 1020 chairs that have serial numbers higher than C238858 do not have a collar, so simply remove the hitch pin and proceed to the next step.
3. Lower the base of the chair all of the way down then disconnect the power.
4. Detach the safety switch bracket from the chair. Using 3/16″ hex key, remove the mounting screw and disconnect the molex plugs to the switches (see Figure 3).
5. Position the support under the chair
upper structure as shown in Figure 4.
Make sure that the tubing is not pinched
and the chair is being properly supported.
6. Remove and save the two washers that
are on the cylinder shaft (see Figure 5).
7. Disconnect and save the sleeve clamp that
holds the tube to the barb (see Figure 5).
Disconnect vent tube from barb.
8. Using diagonal cutters, cut the cable tie
freeing the high pressure hose from the
cylinder. Use the flat blade screwdriver to
remove the retainer clip from the pivot
pin. Push the pivot pin thru the cylinder
body and save both clip and pivot pin.
10. Connect the high pressure
hose to the new lift cylinder and finger tighten the
nut. The nut will be tighten
securely later in the installation.
11. Position the lift cylinder in
the chair and install the
pivot pin and secure with
the retainer clip that was
removed from the old
12. Install the two washers
onto the new cylinder
shaft making sure that the
steel washer is installed
first (see Figure 5).
13. Attach the vent tube to the
barb on the cylinder using
the sleeve that was
removed on disassembly.
Reattach the high pressure hose to the cylinder
body with a cable tie.
14. Manually extend the cylinder rod through the hole in the lower structure.
Install the collar included with the cylinder (if applicable) and attach the
hitch pin to the cylinder shaft (see Figure 2).
15. Securely tighten high pressure hose using the 5/8″ wrench. (Note: The
9/16″ wrench may be required to keep hose from twisting.)
16. Connect power to the chair and with the foot switch raise the chair and
remove the support.
17. Reattach the safety switch bracket and switch connectors. It does not matter which connector plugs onto which switch.
18. Actuate the chair base up and back several times to purge any air in the
lines. If the chair jerks or is noisy it may need Hydraulic Fluid (RPI Part
19. Attach the lower lift arm cover ensuring the slots in the cover’s brackets are
over the support pins (see Figure 6).
20. While base is being lowered, push up on the lower cover to test the safety switch. The chair base should stop immediately. Always be sure to press up in the middle and on each side of the cover when testing.
21. Install the upper lift arm cover and the pump housing cover. Verify proper operation of the chair. Clean any oil that may have spilled during installation.