
8. Remove the two screws
(20)
and washers (22)
holding the air cap (9) to the piston rod (43). Inspect
the o-rings (31,351 under the air cap. Insert a
l/4
in.
(6 mm) diameter metal rod into one of the holes in
the packing nut/wet-cup (41) and loosen it. Pull the
displacement rod (18) and piston rod (43) out the
bottom of the pump head (36). The spacer washer
(42) will come out with the piston rod.
9. Remove the packings and glands from the pump
throat. Clean and inspect all parts.
10. Unscrew the displacement rod cap (57) from the
piston rod (18). Pull the piston rod (43) out the top
of the displacement rod (18).
11. Use wrenches on the flats of the piston rod (43) and
the air valve and piston assembly (2) to unscrew the
piston from the rod. Remove the washer (30), spring
(291,
and rod cap
(57)
from the piston rod (43).
Remove the o-ring (271, v-packing (341, and backup
(33) from the displacement rod cap (57).
12. Disassemble the air valve and piston assembly (2)
and inspect the plates
(6,7)
for dirt that will hold the
valve open and cause continuous exhausting of air.
Clean the parts with a compatible solvent and a soft
brush. Blow dry. If one of the spacers (4) needs
replacement, replace all three.
NOTE:
An optional air valve and piston assembly,
part no. 220-168, is available for severe duty
applications. See page 11.
13. Check the surfaces of the displacement rod (18) and
piston rod
(43)
for wear or scoring by running a
finger over the surface or holding the part up to the
light at an angle. Scoring of these parts will damage
the packings.
14. Remove the tapered spring (28) from the base of the
displacement rod (18) by catching the spring at its
base with a hooked wire and jerking sharply up-
ward. Be careful not to scratch the polished surface
of the displacement rod.
Reassembly
1. Reinstall the spring (28) in the displacement rod (18)
by snapping it in place. Be careful not to scratch the
polished surface of the rod.
2. Reinstall the backup (33”“) and v-packing (34”“) in
the displacement rod cap
(57).
The lips of the
v-packing must face down. Fit the o-ring (27”“) in
place on the outside of the rod cap (57). Slide the
rod cap and the spring (29) onto the piston rod (43).
4. Carefully slide the piston rod (43) into the displace-
ment rod (18). Screw the displacement rod cap (57)
into the displacement rod (18).
5. Reinstall the throat packings one at a time in the
following order:
female gland (38**), bearing
WI**),
three v-packings (39”“) with the lips facing
down, and the male gland (40).
6. Push the piston rod (43) and displacement rod (18)
assembly up into the pump head (36) until it reaches
the top. Use the
l/4
in. diameter rod to tighten the
packing nut/wet-cup (41) just tight enough to pre-
vent leaking.
7. Ensure that the o-rings at the top of the pump head
are in position and fasten the air cap (9) to the piston
rod (43) using the two screws (20) and washers (22).
8. Reinstall the valve plate (461, stop ring (451, and re-
taining ring (26) in the piston body (47). The valve
plate and stop ring may be inverted if they are worn.
9. Reinstall the cup packing (48”“) and retainer ring
(49)
on the piston body
(471,
with the lips of the
packing facing up. Screw the piston body into the
displacement rod (18) and tighten with a wrench.
10. Reinstall the valve plate (461, stop ring (45) and re-
taining ring (26) in the intake valve housing (37). If
the valve plate or stop ring are worn they may be
inverted.
11. Be sure the o-ring (51) is in position at the bottom of
the cylinder (50). Lower the valve housing (37) into
the cylinder, being careful not to scratch the
cylinder’s smooth inner surface. Fasten the intake
housing to the cylinder with the four screws (20)
and washers (22).
12. Carefully raise the cylinder (50) up over the displace-
ment rod (18) and screw it into the pump head (36).
To tighten, use a wrench on the intake valve hous-
ing (37). Never use a wrench on the cylinder.
13. Reinstall the screen (16) in the strainer housing (17).
Screw the strainer assembly (15) into the extension
tube (55) (if used) and then screw these parts into
the intake valve housing (37).
14. Screw the bypass tube
(56)
into the pump head
(36). Reconnect the ground wire if it was discon-
nected during service. Reconnect all hoses.
3. Reassemble the air valve and piston assembly
(2).
Remember that if one spacer (4) needs replacement,
all three must be replaced. Reinstall the washer (30)
on the piston rod (43) and then screw the air valve
and piston assembly (2) onto the piston rod. Use
wrenches and tighten only enough to form an air-
tight seal.
8
305-805