The purge procedure outlined in TM 11-5855-263-40, Chapter 2, paragraph 2-18 must be
modified as indicated below in order to utilize the purge device. The purge device will eliminate
the need to open the monocular assembly. The procedure is performed as follows:
Ensure that valves are closed on the fire control purging tool and nitrogen tank
before connecting equipment. Connect purge kit, fire control to nitrogen tank and
purge device as shown in Figure 1-2.
Set regulator valve handle (1) for zero by rotating control (counterclockwise) until
there is no spring pressure on control.
Open nitrogen tank valve (5). The high pressure gauge (4) will indicate tank
pressure. If pressure is below 50 pounds, replace tank.
Set purge device (8) PUMP/NITROGEN switch (11) to PUMP and LEAK
TEST/PURGE (10) switch to PURGE.
Slowly adjust regulator handle (1) by turning it clockwise until low pressure
gauge (3) indicates 4 PSI. Purge device gauge (9) should indicate 0 1 PSI and
you should hear gas escaping.
Set eye span knob (Figure 1-2) on binocular at 72mm (widest). If purging left
monocular, rotate tilt adjustment lever to top of PAS to expose purge valve.
Using offset screwdriver, remove all purge values, check valves, and preformed
packings. Replace packings if cut or damaged. Apply a small amount of
preformed packing lubricant around packing. Reinstall purge valves and
Make sure eyepiece lockring (Figure 1-2) is tight. If not, go to Chapter 2,
paragraph 2-19, Adjust and Test Monocular in TM 11-5855-263-40.
Using screwdriver, tighten inside purge valves, do not overtighten. Grasp small
knob of purge adapter. Screw thread of purge adapter in outside purge valve until
it stops. Do not overtighten.
Press hose on purge adapter. Using large knob of purge adapter, engage tabs into
slots of purge valve. Rotate counterclockwise 1/8 turn.