a. Unscrew gland nut (3); slide the nut off over
the primary rod (6) and remove the wiper (2) from the
gland nut. Hold the stationary tube assembly (13) and
Refer to figure 4-1 and reassemble the lift cylinder. Note
loosen the gland cap (20). Slide the barrel (1) off the
assembled primary piston, secondary rod assembly (15),
and stationary tube assembly (13). Remove the packing
a. Immerse all parts of the hydraulic lift cylinder in
assembly (10), retainer (12) and packing (4) from the
clean hydraulic oil to lubricate them before Reassembly.
body; remove the back-up ring (24) and preformed
b. Slide the piston rod assembly (15) into the
packing (25) from the cylinder head.
stationary tube assembly (13). Position the gland cap
b. Unscrew the gland nut (17) from the cylinder
(20) on the piston rod assembly and turn the cylinder
head and slide it off the secondary rod assembly (15).
head onto the stationary tube assembly (13). Install
Unscrew the gland nut (3) and slide the assembled
setscrew (22) and lock screw (23) in gland cap (20) and
secondary rod assembly (15) and stationary tube
secure. Torque the cylinder head to a minimum of 300
assembly (13) out of the primary piston.
ft/lbs. Position the packing springs (11) in the retainer
c. Remove lock screw (23) and setscrew (22)
(19) and slide the assembled retainer and adapter into
from gland cap (20). Hold the stationary tube assembly
the cylinder head over the end of the piston rod
(13) and remove the cylinder head.
stationary tube from the piston rod assembly. Slide the
c. Position packing assembly (18) into gland cap
cylinder head off the piston rod assembly.
(20) and tap into place. Position wiper (16) into the gland
nut (17); slide the assembled gland nut over the piston
rod assembly and into the cylinder head. Tighten the
Do not remove the plug (14) unless obviously
gland nut into the cylinder head.
Remove the packing assembly (18),
d. Slide the primary rod (6) over the assembled
retainer (19) and packing springs (11) from The
stationary tube and piston rod assembly. Position the
cylinder head. Remove the two setscrews (26) and
packing springs (11) in the retainer (12); slide the
bleeder valves (27) from the body and stationary tube
assembled retainer and adapter into the primary piston
over the stationary tube assembly. Position wiper (2) in
the gland nut (3). Slide the gland nut over the stationary
tube assembly and tighten the gland nut in the primary
Dry cleaning solvent, P-D-680, used to clean
parts is potentially dangerous to personnel and
e. Position the back-up ring (24) and preformed
property. Avoid repeated and prolonged skin
packing (25) on the cylinder head. Slide the barrel (1)
Do not use near open flame or
over the assembled primary piston, stationary tube
excessive heat. Flash point of solvent is 100° F.
assembly and piston rod assembly; turn the body onto
- 138° F. (39° C. - 59° C.).
the cylinder head and torque to a minimum of 300 ft/lbs.
Tap packing assembly (4) into position in barrel (1).
4-5. Cleaning and Inspection
Position wiper (2) in gland nut (3); slide gland nut over
a. Replace all seals, wipers, and other
the primary piston assembly and tighten in body. Turn
the set-screws (22) into the lock screws (23); turn the
b. Clean all metal parts thoroughly in cleaning
two assembled bleeder valves into the hydraulic lift
solvent P-D-680. Dry thoroughly with compressed air.
Do not allow dirt to get on disassembled parts
Install and bleed the lift cylinder (para 2-6b ).
c. Check all metal parts for cracks, burrs, rust,
distortion, scores, or other damage. Remove burns rust,
with a fine stone. Replace damaged parts.
Section III. HYDRAULIC PUMP
is drawn into the low-pressure side of the unit and is
trapped in the compartments between the vanes and ring
until it is transferred to the high-pressure side of the
The main hydraulic pump is a vane-type rotary pump in
pump where it is discharged. The rotor is mounted on a
which vanes are installed in slots of a close-fitting rotor
ball bearing-mounted drive shaft to assure free rotation.
which rotates in an eccentrically positioned ring. The oil