3.3.1 Hydraulic system.
126.96.36.199 Particle size. The recoil mechanism shall be
filled with hydraulic fluid, bled, and refilled until all air
and measurable moisture are eliminated. The initial and
subsequent filling of the hydraulic system shall be with
hydraulic oil conforming to MIL-H-6083 and filtered through a 5
micron filter. Immediately after mechanical gymnastication, not
to exceed 5 minutes, a 100 ml sample of hydraulic oil shall be
taken from the lowest drain hole of each recoil cylinder.
Samples shall be drained into a suitable container. Each sample
must meet the requirements of Table I.
Hydraulic Fluid cleanliness.
The water content of the hydraulic fluid shall not be more
than 0.1% as determined by standard method of test IAW ASTM
D1744. The hydraulic fluid shall be free of fforeign materials
within the following limits:
below 50 microns
50 - 100 microns
101 - 200 microns
201 - 400 microns
Particles over 400 microns are not acceptable unless they are
fiber or lint. Only two particles of fiber or int are
acceptable, provided they do not exceed the dimensions of 40
microns in width and 3000 microns in length.
L3.1.2 Leakage. During cyclying and after all cycling, no
indication of unusual hydraulic leakage shall OCCUr .
3.3.2 Surface cleanliness. All finish machined surfaces
shall be free of condensation or other foreign residues from the
time of final machining until final assembly. All parts and
assemblies being assembled into the completed mount shall be
free of all foreign material after assembly. Assembly shall be
performed in the controlled environment specified in 6.3.
3.3.3 Part modification. No parts shall be altered or hand-
fitted during assembly unless such modification has been
authorized by an approved drawing change, or is authorized by
instructions presently listed on the drawings.