Displacement Pump Repair
REMOVING AND INSTALLING PUMP
Remove the pump
(Fig. 31)
.
1. Flush the pump. Relieve pressure. Stop the pump
with the piston rod (224) in its lowest position or
carefully rotate the blades of the fan with a screw-
driver to lower the rod.
2. While holding the pump intake valve (223) steady
with a wrench, unscrew the suction tube (71).
3. Disconnect the hose (70).
4. Push the retaining spring (42) up. Push out the pin
(43).
5. Loosen the locknut (47) and unscrew the pump
from the bearing housing (69).
03749A
Fig. 31
69
42
43
47
70
223
224
40
71
216
Install the pump (
Fig. 32).
1. Screw the displacement pump 3/4 of the way into
the bearing housing (69).
2. Hold the pin (43) up to the pin hole in the connect-
ing rod assembly (68) and continue screwing in the
pump until the pin slides easily into the hole. Back
off the pump until the top threads of the pump
cylinder are flush with the face of the bearing
housing and the outlet nipple (40) is straight back.
3. Push the retaining spring (42) into the groove all
the way around the connecting rod.
4. Tighten the locknut (47) very tight–about 70 ft-lb
(97 N.m)–with a 2 in. open–end wrench and a light
hammer.
WARNING
Be sure the retaining spring (42) is firmly in the
groove of the connecting rod, all the way around, to
prevent it from working loose due to vibration. Refer
to Fig. 32.
If the pin works loose, parts could break of
f due to the
force of the pumping action. These parts could be
projected through the air and result in serious bodily
injury, sprayer damage or property damage.
CAUTION
If the locknut (47) loosens
during operation, the
threads of the bearing housing (69) will be damaged.
Be sure to tighten the locknut firmly.
5. Tighten the packing nut (216) just enough to stop
leakage, but no tighter. Fill the wet-cup/packing nut
1/3 full with Graco TSL (65).
Fig. 32
68
FACE OF
BEARING
HOUSING
47 TORQUE TO
70 ft–lb
(95 N.m)
42
43
69
03750
216