Hale MG - Manual (Page 86)

Muscle Pumps
5-22
f. Remove the two remaining 7/16-
14UNC X 1-1/4 inch long cap screws
retaining the relief valve cover to the
pump body. Using a twisting motion,
carefully remove the relief valve
cover
DO NOT PUSH THE RELIEF VALVE TOO FAR
INTO THE PUMP BODY AS IT MAY FALL
INTO THE PUMP BODY AND BECOME
LODGED OR DAMAGED. THE RELIEF
VALVE IS MADE OF BRASS AND IS EASILY
DAMAGED BY PRYING OR HAMMERING.
DAMAGED VALVES MUST BE REPLACED.
g. Remove the retaining ring securing
the relief valve piston to the relief
valve. Gently push the relief valve
into the pump body approximately 1
inch (25 mm), and then pull it back
out in a snap motion. This should pop
the relief valve piston out of the relief
valve body. Repeat if necessary.
NOTE: It is not necessary to remove the relief
valve unless it is damaged. To remove the relief
valve, the relief valve body will have to be
removed and the complete relief valve assembly
will need to be replaced (as it will be necessary to
pry the relief valve body from the pump body,
which will likely damage it).
h. Clean and inspect all of the relief
valve assembly components.
i. Clean all sealing surfaces and install
new O-rings and quad ring seals.
j. Install the relief valve piston in the
stem of the relief valve. Do not push
the relief valve into the pump body.
As it is necessary to start the piston
onto the relief valve stem, push the
piston until you can grasp the relief
stem. Then, pull the relief valve stem
outward while pushing on the relief
valve piston. Once the relief valve
piston is seated against the shoulder of
the relief valve stem, install the
retaining ring.
k. Operate the relief valve by hand to
check freedom of movement.
l. Slide the relief valve cover gasket and
cover over the top of the relief valve
stem to align the relief valve supply
line from the pilot valve in the
original position. Then, apply Loctite
242 to two 7/16-14UNC X 1-1/4 inch
long cap screws and install opposite
of each other. Tighten, but do not
torque.
m. Compress and install the return
spring, and secure it with a washer
and E-clip.
n. Align the indicator light switch
bracket with the two empty holes in
the relief valve cover. Install the two
remaining 7/16-14UNC X 1-1/4 inch
long cap screws. Tighten all cap
screws to 53 ft-lb (72 Nm).
o. Connect the relief valve supply line
from the pilot valve. Also, connect the
drain line.
p. Assemble indicator light switch and
the switch strap. Securely tighten the
two screws.
q. Install the switch strap and light
switch in the switch 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.
r. 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.
s. 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