TM 3-6665-302-34
(6) Unscrew two pins (23) from bottom
(2) Remove tubing (12 and 15) from head
assembly (2).
of guide (18).
(7) Remove guide (18) from pump unit sub-
(3) Remove four screws (1) and lift head
assembly (29).
assembly (2) away from pump unit subassem-
bly (29).
b. Installation.
(4) Remove screw (38), washer (37), and
(1) Position replacement guide (18) in
diaphragm (36) from top of connecting rod as-
pump unit subassembly (29).
sembly (35 ).
(2) Screw replacement pins (23) through
pump unit subassembly into bottom of guide (18).
b. Installation.
(3) Start threads of pin (30) into top of
(1) Position diaphragm (36) against pump
guide (18).
unit subassembly (29) with flat side of outside
edge down.
(4) Place spring rate scale extension (5,
(2) Place washer (37) in concave (cupped)
as shown.
side of diaphragm (36). Secure to connecting
rod assembly (35) with screw (38 ).
(5) Tighten shoulder pin (7) until it fits
below first notch of spring rate scale extension,
(3) Position head assembly (2) with mount-
but not below second notch, as shown in figure
ing holes alined with holes in top of pump unit
3-19.
subassembly (29).
(6) Insert tubing (15, fig. 3-18) through
(4) Install, but do not tighten, four screws
hole in guide (18). Route tubing between guide
(1).
(18) and rollers (31).
(5) Perform alinement procedure (c be-
(7) Attach ends of tubing (15) to tube
low) .
coupling (13) and head assembly (2).
(6) Attach tubing (12 and 15) to head
(8) Connect two springs (14) to guide (18).
assembly (2).
(9) Install cover (para 3-26 b).
(7) Attach cover (para 3-26 b).
3-30. Terminal Lugs
c. Alinement.
(1) Verify that four screws (5, fig. 3-20)
are loose.
a. Removal.
(2) Position air pump jig assembly (4)
(1) Remove cover (para 3-26a).
from M74 test set so that cutout fits over electri-
(2) Disconnect springs (14) from termin-
cal connector (3).
al lugs (9).
(3) Remove nuts (11) and lockwashers
(3) Adjust head assembly (1) so that ports
(10) from terminal lugs (9).
(2) fit in holes in air pump jig assembly (4).
Tighten screws (5).
(4) Remove terminal lugs (9) from pump
unit subassembly (29).
(4) Remove air pump jig assembly (4) and
secure it to the inner lid assembly of the M74
b. Installation.
test set.
(1) Install terminal lugs (9) on upper
screws of motor (7) in the pump unit subas-
3-32. Voltage Regulator (1 A2A1 Al)
sembly (29).
(2) Attach Iockwasher (10) and nut (11)
to each terminal lug (9). Tighten nuts (11 ).
a. Removal.
(3) Connect springs (14) to terminal lugs
(1) Remove pump assembly from detector
(9).
unit assembly (para 3-24).
(4) Install cover (para 3-26b).
(2) Remove two screws (3) and lockwashers
(4).
3-31. Head Assembly and Diaphragm
(3) Tilt module of voltage regulator (6)
a. Removal.
until two terminals are exposed as shown in de-
tail A.
(1) Remove cover (para 3-26a).
