TM 3-6665-302-34
CAUTION
3-21. Air Inlet Heater Assembly
Do not twist or exert excessive side mo-
tion to detector cell or detector cell
a. Removal.
ports may break off in chassis.
CAUTION
(3) While rocking detector cell (37) gently,
pull it directly from chassis (36).
If pliers are needed to loosen air intake
assembly (14), cover jaws of pliers with
(4) Remove three screws (42) and wash-
cloth or tape to avoid damage to the
ers (43 ) from three corners of chassis (36).
assembly.
(5) Unscrew four screws (39). Two will
(1) Unscrew air intake assembly (14) from
remain in chassis (36).
case top assembly (45 ).
(6) Position detector assembly so that plug
(2) Using long-nose pliers, remove pre-
(32) is upward. Remove plug (32) and air filter.
formed packing (27).
(7) Carefully separate chassis assembly
(3) Remove two screws (28) and lockwash-
(36) from case top assembly (45) without dis-
er (29) from heater assembly (30).
connecting tubing (44B) or connector (2735A).
(8) Remove pressure ring (35).
(4) Remove heater assembly from case top
assembly (45).
b. Installation.
b. Installation.
(1) Insert pressure ring (35), with tab cen-
tered at rear of air inlet housing in case top
(1) Insert replacement heater assembly in-
assembly (45 ). Install air filter.
to case top assembly (45) and aline the mount-
ing tabs with the mounting holes in the bottom
(2) Position chassis assembly (36) in case
of the port.
top assembly (45). Be sure that tubing (44B)
is positioned against rounded side of foam boss
(2) Secure with two lockwashers (29)
(half-moon shaped, raised foam piece) in case
and screws (28 ).
top assembly (45).
(3) Install replacement preformed packing
(3) Secure chassis assembly (36) to case
(27) with tabs of packing in the keyways.
top assembly (45 ) with screws (42), washers
(4) Screw air intake assembly (14) into
(43), and screws (39).
case top assembly (45).
(4) Dampen outside of two detector cell
ports with a few drops of water.
3-22. Pressure Ring
(5) Aline ports of detector cell (37) with
corresponding fittings in chassis (36). Press de-
a. Removal.
tector cell into place in chassis (36).
(1) Loosen setscrew (8) and remove crank
(6) Center bail (38) on bottom of detector
cell (37 ) and turn lobed nut clockwise until
(9) from shaft (44A).
fingertight.
(2) Turn lobed nut of bail (38) counter-
(7) Install crank (9) on shaft (44A) and
clockwise and swing bail away from detector
secure with setscrew (8).
cell (37).
Section V. PUMP ASSEMBLY (1A2A11)
ing schedule servicing of the M43 detec-
3-23. General
tor unit. Refer to paragraph 3-28 for
Direct support maintenance personnel are author-
replacement procedures.
ized to repair the M43 detector unit pump as-
sembly by replacing the cover, springs, tubing,
3-24. Removal
coupling, shoulder pin, tube guide, terminal lugs,
head assembly voltage regulator, catches, and
arate detector unit assembly (1) from bottom
rollers. Test pump assembly after repairing (para
case assembly (2).
3-4 b).
NOTE
posite sides of pump assembly (44, fig. 3-17).
Tubing (15, fig. 3-18) is replaced dur-
