TM 5-4520-208-15
(2) Heat the oil and record the reading
(6) Remove three setscrews (16, fig. 34)
from both temperature gages. If the
and remove temperature selector valve
temperature gage removed from the
knob (19), temperature indicator knob
(18), and fuel control valve knob (17).
heater has a reading different from
(7) Remove six screws (15) and (20),
accurate temperature gage, replace
lockwashers (65 and 24), and nuts
temperature gage.
e. Installation.
(66 and 25) and remove control panel
(1.2) from controls and bulkhead.
Note. Steps (1) through (3) pertain only to the
Model BT400-40 heater.
Note. If necessary to gain clearance to
(1) Slide sensing element and capillary
withdraw sensing unit, remove two screws
(38) and lockwashers (37) Disconnect tube
tube through bracket (23, fig. 34) and
assemblies (31 and 32) at pipe-to-tube elbows
position temperature gage (22) on
(30). Move block away from bulkhead and
bracket.
remove temperature gage with capillary tube
Note. If tube assemblies (31 and 32) and
and sensing element.
block were disconnected, connect tube as-
(8) Remove temperature gage (22), with
semblies and secure block to bulkhead with
attached capillary tube and sensing
two screw (38) and lockwashers (87).
element.
(2) Install control panel (12) on bracket
Note. steps (9) through (lo) below per-
and secure with six screws (15 and
tain only to the Model BT400-40-1 heater.
20), lockwashers (65 and 24), and
(9) Remove three setscrews (16, fig. 37)
nuts (64 and 25) to bracket and
and remove temperature selector valve
bulkhead.
knob (19), temperature indicator knob
(3) Position temperature selector valve
(18), and fuel control valve knob
knob (19) and fuel control valve and
(17).
temperature indicator knobs (17 and
(10) Remove six screws (15 and 20), lock-
18) on control valves and secure with
washers (66 and 24) and nuts (65 and
three setscrews (16).
25) and remove control panel (12)
Note. Steps (4) through (6) pertain only
from controls and bulkhead.
to the Model BT400-40-1 heater.
(4) Slide sensing element and capillary
Note. If necessary to gain clearance to
withdraw sensing unit, remove two screws
tube through bracket (23, fig. 37)
(39) and lockwashers (38). Disconnect noz-
and position temperature gage (22)
zle-to-check valve hose assembly (31) and
on bracket.
coupling-to-valve tube assembly (32) at pipe-
Note. If coupling-to-wave tube assembly
to-tube elbows (80). Move block away from
(32), nozzle-to-check valve hose assembly
bulkhead and remove temperature gage with
(31), and block were disconnected, recon-
capillary tube and sensing element.
nect and secure block to bulkhead with two
c. Cleaning and Inspection.
screws (39) and lockwashers (38).
(1) Clean the temperature gage, tube, and
(5) Install control panel (12) on bracket
sensing element with a cloth dampened
and secure with six screws (15 and
in an approved cleaning solvent and
20), lockwashers (66 and 24), and
dry thoroughly.
nuts (65 and 25) to bracket and bulk-
(2) Inspect the temperature gage for bro-
head.
ken glass, damage to tube and sensing
(6) Position temperature selector valve
element, or other damage. Replace
knob (19) and fuel control valve and
entire unit if damaged.
temperature indicator knobs (17 and
d. Test Gage.
18) on control valves and secure with
three setscrews (16).
(1) Insert sensing element of temperature
(7) Insert temperature gage. sensing ele-
gage into a container of oil along with
ment (3, fig. 40) through hole in
a sensing element of a temperature
casing.
gage known to be accurate.
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