piston head is tightened and the retaining pins installed
that show wear beyond the dimensions specified in the
and staked into place. The piston assembly is inserted
inspection standards tables found in most 03 manuals
into the outer cylinder, and the gland nut is tightened to
or MIMs.
a snug fit, backed off two key slots, and locked in place.
Each time the strut is disassembled, all preformed
If the gland nut is too tight, it will result in binding of
and special packings should be replaced, although they
the thrust bearing. Two lock plates, positioned 180
may appear to be serviceable.
degrees apart on the collar and gland nut, are secured
NOTE: Never work on machined surfaces with
with screws and lockwired to hold the gland nut in
metallic tools. Always use brass O-ring tools for
place. Use the double twist method of applying the
checking scratches and removing or replacing seals and
lockwire so that tension of the wire tends to tighten the
gaskets.
nut.
Blend out minor scratches, nicks, and burrs from
Bench Testing
machined surfaces of steel parts with a crocus cloth.
Use aluminum oxide abrasive cloth to polish aluminum
With the strut fully compressed and in the vertical
parts. The smoothness of the repaired area must be
position, service the strut with hydraulic fluid. Install
equal to or smoother than the finish of the surrounding
the air valve on the strut and torque to 100-110
area. Do not attempt to remove normal wear marks
inch-pounds. Place the strut fully extended in a
from the sliding surface of the piston.
horizontal or vertical position and inflate with dry
nitrogen to the normally extended pressure specified in
NOTE: Partial removal of plating from the inner
the MIM or 03 manual. Ensure that the strut shows no
cylinder will condemn the part from further service,
leakage after a 1-hour interval.
pending replating of the cylinder. Portable brush-type
plating equipment is available in some intermediate
If the strut fails the bench test, it is tagged to show
maintenance activities for touch-up plating of minor
the portion of the test that failed. Then it is deflated,
areas.
flushed with preservative hydraulic fluid, and
forwarded to the next higher level of maintenance.
Areas with damaged paint or other protective
finishes must be restored to a serviceable condition.
If the strut passes the bench test and is not to be
installed on an aircraft immediately, flush with
If any bushings require replacement, the mating
preservative hydraulic fluid before sending it to supply.
bushing must also be replaced.
If any parts other than those listed as replaceable at
Reassembly
the intermediate level of maintenance are faulty, tag the
strut and forward it to the next higher level of
Reassemble the strut assembly in essentially the
maintenance. The VIDS/MAF is closed out to account
reverse order of disassembly. Exercise adequate
for man-hours expended in attempting repairs before
precautions to ensure that dirt, dust, grit, or other
the strut is declared beyond the capability of
foreign matter does not enter the strut during assembly.
maintenance (BCM). If a Quality Deficiency Report
Contamination of parts can cause a definite failure.
(QDR) form was attached to the strut by the removing
Guarding against contamination cannot be over-
organizational maintenance activity, complete the QDR
emphasized.
and submit it according to the instructions provided in
Observe the torque values specified in the 03
OPNAV Instruction 4790.2 (series).
manual or MIM. Where a specific torque value is not
Any unusual failure or strut malfunction should be
specified for a threaded part, tighten the part according
reported by the submission of a QDR so that failure
to the standard torque values provided in the Structural
trend patterns or isolated instances may be reviewed for
Hardware Manual, NAVAIR 01-1A-8. Some structural
possible higher echelon action. Forward the No. 4 copy
repair manuals and maintenance instructions manuals
of the MAF and the hard copy of the QDR with the strut
also contain this information. On some parts, such as
to the next higher level of maintenance.
the strut gland nut, tightening should conform to
acceptable shop practices and common sense, unless
Q13-26. All drop checks should be performed in
otherwise specified.
accordance with what manual?
Lightly coat all preformed packings with hydraulic
Q13-27. What is the first step in performing a drop
fluid. After all seals and parts are properly installed, the
check?
13-19
