handling, remove the wheel (with tire and brake
With the piston supported, the collar or gland nut is
assembly).
unscrewed and the piston withdrawn from the cylinder.
Pour the hydraulic fluid into a suitable container, and
place the piston/axle assembly in a clean work area.
Inspect the hydraulic fluid for evidence of rubber or
CAUTION
metal particles that might indicate wear conditions
Before removing a wheel assembly from an
within the strut.
aircraft, deflate the tire completely. To ensure positive
Remove the pin retainer and three pins from the
removal of all pressure from the tire, you should
piston head; then remove the piston head and the recoil
remove the valve core and attach a "deflated tire" tag
valve. On some aircraft the retaining pins are press
to the valve stem after deflating the tire.
fitted while on others they are screwed in. Remove the
metering pin assembly, follower, thrust bearing
Remove all attached fairings and door connecting
assembly, adapter, delta ring, and other removable parts
rods. Disconnect and cap the hydraulic brake lines and
in the order in which they are installed on the piston
fittings. Disconnect electrical connections at the
assembly, as shown in figure 13-13.
cannon plugs, and remove wiring from clamps as
The cylinder walls, piston head, adapter, follower,
necessary. Retain all removed hardware in a cloth bag.
and bearings should be inspected for excessive wear
Disconnect the drag brace by partially pulling the
and sharp edges. Minor nicks, scratches, or sharp edges
upper torque arm pin. After disconnecting the drag
can be polished out with a crocus cloth (steel parts) or
brace, reinstall the pin and nut to retain the torque arm.
aluminum oxide abrasive cloth (aluminum parts).
The side brace is generally removed with the strut
Coat all seals and backup rings with hydraulic fluid
assembly. It should be disconnected at its upper end by
and install in the reverse order of the disassembly
removing the nut and pin. After the side brace is
sequence. Ensure that the adapter, follower, and recoil
disconnected, reinstall the pin.
valve are facing in the right direction on the piston
assembly. Once the piston assembly is reassembled,
If equipped with a shrink rod, disconnect the shrink
quality assurance should check for proper reassembly
rod from the strut, not from the aircraft. This is
before inserting it into the cylinder.
accomplished by removing the rod fitting bolt at the
bottom of the rod. When the shrink rod is disconnected,
The inner surface of the cylinder and the outer
the nut and bolt should be reinstalled in the fitting for
surface of the piston are coated with hydraulic fluid,
safekeeping.
and the piston is immediately installed in the cylinder.
The gland nut is tightened and the lock screws installed
Support the recoil strut and partially pull the
and safety wired. The torque arms are reconnected and
crossbolt at the top of the strut to disengage it from the
the strut lowered to its normal extended position. All
support structure. Lower the strut and reinstall the bolt
linkage, hydraulic lines, wire bundles, and the brake
and nut.
and wheel assemblies are installed in the reverse order
Installation essentially reverses the removal
of their removal. The strut is serviced as required by the
procedures. With the aircraft still on jacks, carefully
applicable MIM or maintenance requirements card.
move the top of the recoil strut into place to engage the
Proper servicing is very important. Not all struts
support structure fitting. Install the crossbolt, washer,
are serviced in the standard manner. Consult the
nut, and cotter pin. Connect the shrink rod to the shrink
appropriate MIM to prevent improper servicing and
rod fitting. Connect the side brace to the support
subsequent landing gear or structural failure. All
structure fitting. Partially pull the upper torque arm pin
linkage on the lower strut that was disturbed must be
and connect the drag brace. Reinstall the pin, tongued
lubricated, the brakes bled, and the brakes and the
washer, nut, and cotter pin.
landing gear systems operationally tested.
Assemble the brake and wheel to the strut axle,
bleed the brake, and service the strut as specified in the
STRUT REMOVAL AND REPLACEMENT
aircraft MIM. Ensure that the air valve is safety wired
before charging the strut with nitrogen. After the strut
To remove a strut assembly, first jack the aircraft
has been serviced with hydraulic fluid and nitrogen,
according to instructions furnished in the applicable
tighten the air valve to the specified torque value
MIM. To reduce the weight and allow for easier
required by the MIM. Replace all removed fairings,
13-14
