a. BFV TOW/TOW2 SUBSYSTEM (M2, M3,
M2A1, M3A1, M2A2, AND M3A2 (figs. 3-47
through 3- 52).
(1) Backup Sight, PN 12316793, (fig. 3-47).
The end assembly for the M17BlC (fig. 3-46)
is purged and charged in the same manner as
the M17A1 and M17C with the exception of
removing two outlet screws instead of one.
Refer to para 3-12.c.(2) for procedures.
Figure 3-46 M17B1C End Assembly
Figure 3-47 Backup Sight, PN 12316793
The backup sight must be moved to gunners
position and the commanders hatch cover
opened and secured before purging and charg-
ing. Refer to TM 92350-252-10-2.
(a) Perform purging and charging procedure para
(b) Open valve stem (outlet screw) on outer head
assembly onlv three turns for purge procedure.
(c) Purge instrument at 5 psig for 5 minutes.
(d) Close valve stem (outlet screw) on outer head
(e) Charge instrument at 5 psig.
(f) Leak test for minimum of 5 minutes.
(g) Close hatch and secure commanders hatch cover.
(2) Integrated Sight Unit (figs. 3-48 and 3-49).
Figure 3-48 Integrated Sight Unit
ISU seals could rupture if pressure is too
high. Never let low pressure gage get higher
than 4 psig.
(a) Open and secure gunners hatch cover. (Refer to
TM 9-2350-252-l0-2 for M2, M3, M2A1, and M3A1 or
TM 9-2350-282-l0-2 for M2A2 and M3A2.)
(b) For M2, M3, M2A1, and M3A1 only, open sight
shield assembly per TM 9-2350-252-202-3.
(c) For M2A2 and M3A2 only, remove ballistic
sight shield assembly per TM 9-2350-284-20-2-3.