MAINTENANCE
ITEMS
MAINTENANCE ITEM NO.23
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NO.51
VG2I Squadron LANDING GEAR STRUT SEAL REPLACEMENT 4/5/05
General Notes
For the main gears there should be no fuel in the side being reworked and
only one side should be reworked at a time.
Material required:
Strut Seal P/N 1859, Strut Cap 0-Rings MS28775-116, 221 Hydraulic oil MIL-H-5606
Gear Lube, SAE #90 or Chain Saw Bar Oil, Automotive silicone sealant
Ref. Varga MM Sections 2.10.l and 6.5.1 thru 6.6.1.
as required. Torque hardware per section 2.8 of the MM.
Position Aircraft for Seal Replacement
Elevate nose gear and place cinder block under nose wheel.
Jacking under main gear axle, elevate aircraft and place cinder blocks under
each main wheel.
Install wheel chocks.
Remove Gear Inner Strut (Ref. Fig 6.4)
PRIOR TO TAKING WEIGHT OFF LANDING GEAR:
Remove “DOT” plug on wing upper surface and loosen 7/16 strut bolt at center
of gear outer strut 6 turns.
Note: This is a critical step. Make sure the 5/8
socket makes 100% contact. An impact wrench is suggested.
Raise wing high enough to remove inner strut, (24
inches between floor and bottom of outer cylinder), and support aircraft per MM
2.10.2
Note: A length of water piper inserted into the axle is helpful at this point
Remove bolts attaching brake caliper to gear.
Remove axle nut and remove wheel.
Remove hardware attaching torque link to inner
strut, and gear bushing seal clamp (28).
Use care not to bend clamp. Place support or jack under inner cylinder.
Unthread the 7/16 bolt at top of outer strut. Inner cylinder is now free to be
withdrawn from outer cylinder by removing jack or support.
Remove the 3 socket head cap screws (24) from upper plastic bushing and slide
off the upper bushing (19) and end cap (23). Dump oil from inner cylinder.
Slip off the lower plastic bushing (3) and the worn
seal (18). Clean and inspect all removed parts for reinstalling.
Install new seal, P/N 18591, and note the following: Seal has a single lip and
if installed lip “up” it will keep oil in better. If installed lip
“down” it will keep dirt out better than it keeps oil in.
Reinstall Lower Bushing
Apply a thin coat of silicone sealant to outer surfaces of lower plastic bushing
and the new seal to prevent leakage of oil at the outer strut.
Reassemble upper strut cap/bushing assy. In reverse order of the disassembly.
Tighten the socket head screws (24) but do not over torque
Reinstall Gear Inner Strut (ref. 112.6.4)
Carefully insert inner strut into outer strut. A mechanics “bullet” in the
outer cylinder location for the strut bolt (4) will help in positioning plunger
(27).
Using jack, compress springs and reinstall strut bolt (4) finger tight.
With lower strut bearing and new seal in place
secure by installing seal clamp.
Reconnect torque link using retained hardware.
Install cotter pins,
Reinstall wheel assy. Torque axle nut. Install
cotter pin.
Reinstall brake caliper. Check wheel rotation,
Service Gear Per Section 2,14,2 3
Pump ‘A cup of Auto Gear Lube 90# or Chain Saw Bar Lube oil into outer
cylinder for lubrication of upper and lower plastic bearings. Install screw
(49).
Lift aircraft, remove supports, and lower aircraft
on to its gears.
Remove strut bolt (4). Pump, (very slowly),1 and 2/3’s cup of MIL 5606 into
the inner cylinder. Reinstall strut bolt (4) and torque.
Operate recoil action of landing gear by lifting of wing several times and check
that the MIL 5606 oil level is 7” down from top of outer cylinder. Install
screw (49) in strut bolt (4). Install wing “DOT” plug. Verily gear moves
without binding.