Hale MG - Manual (Page 87)

Muscle Pumps
5-23
poppet and the light goes out. The
switch is now in the proper position.
Tighten the screws holding the switch
strap to the bracket.
t. Fill the pump and test the valve for
proper operation and leaks.
3. QG Relief Valve
(Refer to figure 6-16)
a. Before removal match mark the relief
valve housing and pump body for
proper assembly.
b. Disconnect the line to the sensing
valve and drain valve. Make note of
the wire connections.
c. Disconnect the indicator light switch.
d. Remove the four 7/16-14UNC X 1-
1/4 inch long cap screws attaching the
relief valve assembly to the pump
body.
e. Using a twisting motion, remove the
relief valve assembly.
f. To disassemble the valve, remove the
indicator light switch, remove the
cover-retaining ring and slide the
cover out of the relief valve body.
g. Apply a small amount of pressure to
the relief valve piston and remove the
piston-retaining ring. Carefully
release the pressure held to the piston
by the spring.
h. Remove the relief valve stem from the
opposite end, sliding the relief valve
stem out of the piston.
i. Reach through the center hole of the
piston and pull the piston out of the
indicator switch end of the relief valve
body. Then, remove the piston spring.
j. To assemble and install the valve, first
clean and inspect all components.
k. Clean all sealing surfaces and install
new O-ring seals.
l. Install the relief valve into the relief
valve body.
m. Install the piston spring by sliding the
piston into the relief valve body while
at the same time sliding the piston
onto the relief valve stem.
n. Apply light pressure to the piston to
compress the piston spring and install
the piston-retaining ring.
o. Slide the cover into the relief valve
body. Then, install the cover-retaining
ring.
p. Slide the relief valve assembly into
the pump body with the side marked
“top” up, being careful not to damage
the O-rings.
q. Apply Loctite 242 to the four 7/16-
14UNC X 1-1/4 inch long cap screws
and install the assembly in the pump
body. Tighten to 53 ft-lb (72 Nm).
r. Install collet fitting tight into the valve
cover. Back off 1 to 1-1/2 turns.
s. Install the light switch in the collet
fitting. Leave the collet holding the
light switch slightly loose to allow the
switch to move in and out for
adjustment.
t. Connect the panel mounted indicator
light or a suitable test light to the
switch terminals. With the light
switch pulled nearly all the way out,
the light should be lit.
u. With the pump not running and the
relief valve fully closed, push the light
switch in until the light goes out. Hold
the collet fitting with a wrench to
prevent it from turning, and tighten
the collet.