Hale MG - Manual (Page 106)

Muscle Pumps
5-42
n. Apply a light coat of grease to the O-
ring groove and insert a new O-ring
into groove.
o. Install discharge connector and secure
in place by tightening T-bolt nuts to
20 ft-lb (27 Nm).
p. Install jam nut and thread cap.
q. Reconnect discharge piping.
r. Test operate apparatus and check for
leaks.
s. Return apparatus to service.
4. Valve Stem Seal Replacement
a. Place apparatus out of service in
accordance with departmental
procedures.
b. Open all drains and release pressure
from pump system.
c. Gain access to the valve.
d. Remove the 7/16-14 UNC X 1 inch
long hex head cap screws that secure
the top collar or bottom collar
assembly to the pump body.
e. Remove collar assembly from valve
body.
f. Remove old seal ring from stem.
Make sure stem and seal ring groove
are clean then install new seal ring on
stem.
g. Install new collar seal ring on collar
assembly then install collar assembly
in valve.
h. Install the 7/16-14 UNC X 1 inch long
hex head cap screws.
i. Tighten screws to 40 ft-lb.
j. Reattach any items that were removed
from valve to gain access to the top
and bottom collars.
k. Test operate pump and check for
leaks.
l. Return apparatus to service.
5. Drain Valve Repair Procedures
a. Type HD Drain Valve:
(Refer to figure 6-21)
If the type HD drain valve is leaking
the seals must be replaced. Replace
the seals using the following
procedures:
1) Place apparatus out of service in
accordance with department
procedures.
2) Open all drain valves to make
sure all pressure is relieved from
the pump.
3) Gain access to inlet fitting on the
valve and disconnect the hose or
tube from the valve.
4) Holding stem with a pair of pliers
if necessary and remove the knob
from the valve stem.
5) Loosen or remove screws that
hold valve body to the operator
panel and remove valve assembly
to suitable work area.
6) Remove the piston-retaining ring
from the valve body.
7) Slide the piston assembly out of
the valve body.
8) Remove the old seal rings from
the valve piston.
9) Clean all parts and check for
excessive wear or pitting.