TM 5-6640-212-14
CHAPTER 5
DIRECT SUPPORT AND GENERAL SUPPORT
MAINTENANCE INSTRUCTIONS
b. Photocell Removal.
5-1. Water Pump.
(1) Loosen four captive cover screws on
a. Removal and Disassembly. Close circuit breaker
instrument front panel and pull meter forward and out of
to water pump. Tag and remove wires from motor.
housing.
Close all valves to the suction and pressure sides of the
(2) Remove any dust that might have
pump. Then proceed as follows:
accumulated, pry up plug button on top of meter.
(1) Open pipe plug at bottom of pump, and drain
(3) Turn setting knob clockwise until red pointer is
pump.
at top of scale. Setting arm carrying photocell and light
(2) Loosen both unions at pump housing, and
source is then visible through hole to side of setting.
remove pump and motor as an assembly.
(4) To remove photocell, pull up without turning.
(3) Remove the four casing to bracket screws and
c. Light Source Removal.
the mounting-foot screws. This permits the removal as
an assembly the motor, bracket, foot, and impeller.
(1) Loosen four corner screws on instrument front
(4) Disassemble the impeller (5) from the motor
panel and pull meter forward and out of housing.
shaft holding the motor shaft with a screwdriver engaging
(2) Remove any dust that might have
the slot which is covered by a cap at the opposite end of
accumulated, pry up plug button on top of meter.
the motor. Turn impeller free from the shaft's 7/16 in.
(3) Turn setting knob clockwise until red pointer is
right-hand thread.
at top of scale. Setting arm carrying light source and
b. Cleaning. Cleaning all parts in the pump is
photocell is then visible through hole to side of setting.
essential before reassembling the pump. Be sure that
(4) To remove light source, press down on light
no grit remains between the surfaces of the mechanical
source and turn counterclockwise.
shaft seal.
d. Photocell Installation. Replace new cell with
c. Troubleshooting.
Refer to table 5-1 for
window facing light source, replace plug button and
troubleshooting procedures for the water pump.
replace meter in housing. After installation, correlating
d. Assembly. Be sure all connections are made air
the instrument must be done, refer to subparagraph g.
and water tight, and assemble in the reverse order of
e. Light Source Installation. Install with open side
disassembly.
of reflector facing photocell.
CAUTION
NOTE
Do not run pump unless it is filled
When either photocell or light source
is replaced correlating of instrument
with water to keep the seal lubricated.
is usually required.
5-2. Pyrometer.
f. Window Installation. Install window in reverse
a. Window Removal.
order of removal.
(1) Remove four captive cover screws (fig. 5-2)
g. Correlating the Instrument.
from cover assembly.
(1) This should be done if green indicating and red
(2) Loosen setscrew and remove setting knob.
index pointers do not coincide at point where control
(3) Remove front cover carefully from instrument.
action is installed.
(4) Remove window retainer spring from front
cover.
(5) Remove glass window from front cover.
5-1
