TM 3-6665-302-34
(2) Insert preformed packing (37) around
(2) Unsolder wires from terminals of heat-
outer circular portion of cell block assembly (75).
er module (1, fig. 321 ).
(3) Install fluid fittings (40) in bottom of
(3) Remove screws (31) from bottom of
cellblock assembly (75) as follows:
chassis subassembly (56, fig. 321
).
(a) Insert fitting stopper assembly from
(4) Remove heater module (1, fig. 3-21
).
M74 test set into fluid fitting (40).
b. Installation.
(b) Dip fluid fitting (40) into distilled or
(1) Position heater module (1) on chassis
deionized water.
subassembly (56).
(c) Insert fluid fitting (40) into threaded
mounting hole on bottom of cell block assembly
(2) Coat threads of screws (31) with seal-
(75).
ing compound (item 2, table 11). Install screws
through bottom of chassis subassembly (56) and
(d) Screw fitting stopper assembly clock-
wise until fluid fitting (40) is secure.
tighten screws.
(e) Pull fitting stopper assembly from
(3) Using figure 32 as a guide, solder wires
fluid fitting and return fitting stopper assembly
to terminals of heater module (1, fig. 3-21
).
to M74 test set.
(4) Coat soldered connections with sealant
(4) Solder wires to terminals on side of cell
from coating kit (item 6, table 1-1).
block assembly (75) and connect resistors (76
(5) Install chassis assembly to case top as-
and 77). Coat soldered joints with sealant from
sembly (para 337).
coating kit (item 6, table 11).
(5) Coat mating surface of cell block as-
4-12. Shaft Assembly
sembly with silicone primer (item 7, table 1-1).
)
Allow silicone primer to dry for approximately
a. Removal.
1 hour before proceeding.
(1) Remove chassis assembly (para 3-36).
(6) Insert two screws (71) through bottom
of chassis subassembly (56).
(2) Remove retaining rings (45 and 47).
(7) Coat mating surface of chassis subas-
(3) Remove shaft assembly (67), detent
sembly (56) with insulating compound (item
(46), washers (48 and 50), and spring (49).
1, table 11). Immediately place cell block as-
(4) Remove retaining ring (65) from in-
sembly (56) in position over two screws (71).
side groove of pin (63).
Tighten screws (71 ) using temporarily installed
nuts on each screw (71).
(5) Withdraw pin (63) from chassis sub-
assembly (56). Remove bellcrank assembly (66),
(8) Install and tighten two screws (78)
spring (62), and washer (61).
in top of cell block assembly (56).
(9) Wipe off excess insulating compound.
(6) Unscrew screws (64) and remove nuts
(51), lockwashers (52), clip (53), and retaining
(10) Dress and solder two wires to electrical
ring (60).
connector on cell block assembly (56).
(11) Cover connector with sealant from coat-
b. Installation.
ing kit (item 6, table 11). Cover wires and
(1) Position clip (53) on chassis subassembly
joints with sealant.
(56) and insert screws (64) from bottom.
(12) Attach tubing (11 and 21, fig. 3-21
(2) Install lockwashers (52) and nuts (51)
) to fittings on cell block assembly (75).
on screws (64) and tighten.
(13) Unscrew and remove nut from screws
(3) Install retaining ring (60) on one end
(71, fig. 3-21 ) .
of pin (63). Slip washer (61) and spring (62)
(14) Install chassis assembly to case top as-
on pin (63).
sembly (para 3-37).
(4) Position replacement bellcrank assembly
(66) between shaft mounting holes. Insert pin
4-11. Heater Module
(63) through mounting holes in chassis sub-
a. Removal.
assembly (56) and bellcrank (66). Install retain-
(1) Remove chassis assembly (para 3-36).
ing ring (65) on inside groove of pin (63).
