4.
Bleed the air out of the lift system.
Outer Lift Cylinders
Repacking
Tools: 9650080 - Triplex Gland Nut Tool
1.
Operate the lift function so that the outer
cylinders are extended about 12 to 24 inches.
2.
For this procedure, use a chain with a
capacity that is greater than the weight of the
mast. Do not use blocks to support the
elevated mast sections. Use the chain to
secure the top crossbar of the outer rail to the
bottom crossbar of the middle rail.
3.
Slowly lower the mast so that the chain
supports the weight of the elevated sections.
The carriage will be completely lowered.
4.
Remove the screw securing the outer cylinder
rod to the top crossbar (do not allow the rod to
spin). If resealing both cylinders, remove both
screws at this time.
5.
Open the manual lowering valve so that the
cylinder rods retract into the cylinder. Be
careful not to lose any shims on the top of the
rods. Note their location for reinstallation
(typically, only one side will be shimmed).
6.
Use a prybar or a large wrench on the port at
the base of the cylinder to prevent the cylinder
from rotating while loosening the gland nut.
Use the proper gland nut tool to loosen and
remove the gland nut from the top of the
cylinder.
7.
Install new seals and lubricate them with clean
hydraulic fluid. Carefully slide the gland nut
over the cylinder rod and thread it into the
cylinder. Make sure the cylinder does not
rotate while tightening the gland nut. The
gland nut should be torqued in excess of 100
lb-ft.
8.
Close the manual lowering valve. Operate
the lift control to extend the cylinder rods to
the top crossbar. Make sure any shims that
were found on top of the rods in Step 5 are in
place. Install and tighten the hardware
removed in Step 4.
9.
Slowly raise the mast just enough to take the
tension off the chain. Remove the chain from
the mast and lower it completely.
10. Check for leaks as described in the Checks
and Adjustments section. If the mast leans to
one side at full extension, the cylinder rods
are not properly shimmed (refer to Checks
and Adjustments for shimming instructions).
E
lectric
C
ounterbalance
H
igh
O
utput
Elevating
3/10/00
7.9
FIGURE 7.7 - OUTER CYLINDER
1
2
3
4
4
5
5
6
7
1. Wiper
2. Rod Seal
3. Gland
4. Back-up Ring
5. O-Ring
6. Rod Assembly
7. Wear Ring
8. Piston Ring
9. Spacer
10. Cylinder Shell
8
9
7
10
