Hale MG - Manual (Page 89)

Muscle Pumps
5-25
y. Apply Loctite 242 to the four 7/16-
14UNC X 1-1/2 inch long cap screws
and install the new gasket and relief
valve assembly to the atmosphere
dump. Tighten to 53 ft-lb (72 Nm).
z. Apply Loctite 242 to the 7/16-14UNC
X2 inch long cap screw, install the
sensing valve and tighten. Make sure
the arrow on the sensing valve points
upward.
aa. Assemble indicator light switch and
the switch strap and securely tighten
the two screws.
bb. Install the switch strap and light
switch assembly in the switch bracket.
Attach flasher assembly to bracket.
Leave the two screws attaching the
switch strap to the switch bracket
slightly loose to allow the switch to
move in and out for adjustment.
cc. Connect the panel mounted indicator
light or a suitable test light to the
switch terminals. With the light
switch plunger not in contact with the
end of the poppet, the light should be
lit.
dd. With the pump not running and the
relief valve fully closed, push the light
switch in until the switch plunger
makes contact with the end of the
poppet and the light goes out. The
switch is now in the proper position.
Tighten the screws holding the switch
strap to the bracket.
ee. Connect the line to the sensing valve.
ff. Fill the pump and test the valve for
proper operation and leaks.
5. Sensing Valve
(Refer to figure 6-13)
a. Disconnect the following lines at the
sensing valve:
q Pilot valve discharge line
q QG relief valve line
q PG relief valve line
q Sensing valve pump suction line
q Drain lines
b. Remove the 7/16-14UNC X2 inch
long sensing valve mounting cap
screw.
c. Remove the four 5/16-18UNC X 1
inch long cap screws attaching the
control body to the rear of the spring
housing. Remove the control body,
being careful not to lose the sensing
valve spring.
d Remove the control valve from the
sensing valve body.
e. Unscrew the sensing valve from the
diaphragm, being careful not to
damage the control valve. Remove the
diaphragm.
f. Before installing the sensing valve,
clean all components.
ALWAYS REMOVE THE SENSING VALVE
SUCTION INLET SCREEN. CLEAN OR
REPLACE AS NECESSARY. THE SCREEN IS
LOCATED IN THE SUCTION SIDE OF THE
PUMP. FAILURE TO DO SO MAY RENDER
COMPONENTS INOPERATIVE.
g. Install a new diaphragm on the
diaphragm clamp. Apply Loctite to
the threads on the control valve and
install the control valve into the
sensing valve body.
h. Install the sensing valve spring into
the valve body cover.