TM 3-6665-302-34
67 Shaft assembly
53 Clip
37 Preformed packing
67A Gasket
54 Screw
38 Preformed packing
55 Contact
67B Plate
39 Preformed packing
55A Terminal stud
67C Screw
40 Fluid fitting
56 Chassis subassembly (A4)
68 Screw
41 Strap
69 Catch
57 Screw
58 Catch
70 Screw
59 Fluid fitting
71 Screw
44 Strip nut
60 Retaining ring
72 Screw
45 Retaining ring
61 Washer
73 Screw
46 Detent
74 Contact
75 Cell block assembly (A3)
64 Screw
76 Resistor (A3R1)
49 Spring
65 Pin
77 Resistor (A3R2)
50 Washer
65A Tip jack
78 Screw
51 Nut
66 Bellcrank assembly
52 Lockwasher
Figure 3-21
. Chassis assembly, exploded view - Continued
cell block assembly (75), grasp the fluid
(4) Slip other end of tubing (28) over fluid tube
fitting (40 or 59) with needle-nose pliers and
until tubing end contacts separator (27).
unscrew it.
(5) Install fresh reservoir assembly.
(4) Remove fitting stopper assembly from fluid
(6) Install bottom case assembly (para 3-8).
fitting.
(5) Remove screws (67 C), plate (67 B), and gasket
(67A).
b. Installation.
a. Removal.
(1) Insert fitting stopper assembly from M74 test
(1) Remove chassis assembly from top case
set into fluid fitting (40 or 59).
assembly (para 3-36).
(2) Moisten exterior threads of fluid fitting (40 or
(2) Remove preformed packing (37) from cell
59) with saliva.
block assembly (75).
(3) Insert fluid fitting into threaded mounting
(3) Remove preformed packing (38) from cell
hole in chassis subassembly (56) or cell block
block assembly (75).
assembly (75).
(4) Remove preformed packing (39) from cell
(4) Turn fitting stopper assembly clockwise until
block assembly (75).
end of fluid fitting (40 or 59) is flush with surface of
b. Installation.
chassis subassembly (50) or cell block assembly (75).
(1) Insert preformed packing (38) around inner
If fluid fitting cannot be installed using fitting
circular portion of cell block assembly (75).
stopper, remove fitting stopper. Insert eraser end of
(2) Install preformed packing (37) around outer
wooden pencil approximately halfway into fluid
circular portion of cell block assembly (75).
fitting. Turn fluid fitting clockwise until flush with
(3) Install preformed packing (39) on fluid fitting
surface. Remove pencil.
of cell block assembly.
(5) Pull fitting stopper assembly from fluid fitting
(4) Install chassis assembly in case top assembly
and return fitting stopper assembly to M74 test set.
(6) Install gasket (67A), plate (67B), and screws
(67C).
(7) Install pump assembly in detector unit
assembly (para 3-25).
a. Removal.
(1) Remove pump assembly from detector unit
3-42. Catches
assembly (para 3-24).
(2) Insert M74 test set fitting stopper into fluid
a. Removal.
fitting (40 or 59)
(1) Remove pump assembly from detector unit
(3) Turn fitting stopper assembly coun-
assembly (para 3-24).
terclockwise until fluid fitting is free of threaded
(2) Remove two screws (57) to remove catch (58)
mounting hole. If fluid fitting will not turn, remove
and remove two screws (70) to remove catch (69).
fitting stopper.
b. Installation.
CAUTION
(1) Install catch (69) with two screws (70) and install
Being careful not to damage the molded
catch (58) with two screws (57).
threads on the chassis subassembly (56) or
Change 2
