49. LUBRICATION.
_a. Gun group._ War Department Lubrication Order No. 4001 (Fig 31)
shows the parts which require lubrication, the lubricants, and the
intervals.
(1) _Lubricants._ Grease, general purpose, No. 1 is used, except for
temperatures below freezing, when grease, general purpose. No. 0 is
used. The bearing surfaces should be lightly coated with the grease.
(2) _Frequency of lubrication._ The surfaces of the ignition-head body
which touch the spring case should be lubricated after each use of
the weapon. Other parts are lubricated after six firing missions, six
training sessions, or oftener. All should be thoroughly cleaned (Pars
52, 55, and 56) with gasoline, dry cleaning solvent, or other solvent,
then dried before lubrication. If the gun is disassembled for any other
reason, it should be lubricated before reassembly.
(3) _Records._ To ascertain when six missions have been fired, a record
of firing (Par 2) should be kept with each flame thrower.
_b. Tank group._ The tank group ordinarily requires no lubrication.
However, it may under the following exceptional circumstances:
(1) If the tank group has been immersed in water for several hours,
the flexible shaft of the pressure valve may have lost its lubricant.
If so, remove the shaft (Par 66 _b_) and inspect. If lubricant is not
present, as indicated by difficulty of movement after removal, dip
the shaft in solvent to clean and then dip in warmed grease, general
purpose, No. 1. Replace shaft in valve.
(2) If filling or safety-head plugs (Figs 39 and 40) tend to stick
to fuel tanks, apply grease, general purpose, No. 1 (No. 0 if below
freezing temperatures) before replacing plugs.