Displacement Pump Repair - Graco A Series Instructions-Parts List Manual

WARNING
Before doing this procedure, follow the Pressure
Relief Procedure Warning on page 24 to reduce
the risk of a fluid injection injury , splashing in the
eyes or skin, injury from moving parts or electric
shock.
NOTE: Packing Repair Kit 222–343 is available. For the
best results use all the parts in the kit. Parts in-
cluded in the kit are marked with an asterisk, for
example (212*) in the text and drawings.
Removing the Pump
Refer to Fig 36–1
1. Flush the pump, if possible, and relieve pressure
again. Stop the pump with the piston rod (223) in its
lowest position.
2. Unscrew the swivel union (33) from the pump intake.
Hold the wrench on the pump intake valve (222) to
keep the pump from loosening.
3. Unscrew the hose (30) from the swivel union (31).
4. Use a screwdriver to push the retaining spring (64)
up and push out the pin (63).
5. Loosen the locknut (65) and unscrew the pump from
the bearing housing (62).
6. Go to Disassembling the Pump on the bottom right
side of this page.
62
64
223
63
65
31
33
Fig 36–1
Reinstalling the Pump
1. Rotate the crankshaft so the connecting rod (60) is in
its lowest position. Push the pump piston rod (223) all
the way down into the pump cylinder (216). Screw
the pump into the bearing housing (62) until you feel
the piston rod pressing against the connecting rod.
Now, unscrew the pump until the swivel union (31) is
straight back, and then unscrew one more complete
turn.
307–958

DISPLACEMENT PUMP REPAIR

.
DETAIL OF
INTAKE VALVE
216
215
*207
*204
*206
222
.
Refer to Fig 36–2
2. Torque the locknut (65) to 70 ft–lb (95 N.m). Refer to
the CAUTION, below.
CAUTION
If the locknut loosens during operation, the threads
of the bearing housing (62) will be permanently
damaged. Be sure to tighten the locknut firmly.
3. Align the holes in the piston rod (223) and the con-
necting rod (60), and install the pin (63). Push the re-
taining spring (64) into the groove all the way around
the coupling. Refer to the WARNING, below.
WARNING
Be sure the retaining spring (64) is firmly in the
groove of the connecting rod, all the way around,
to prevent it from working loose due to vibration.
See Fig 36–1.
If the pin works loose, it or other parts could break
off due to the force of the pumping action. These
parts could be projected through the air and result
in serious bodily injury or property damage, includ-
ing damage to the pump, connecting rod or bearing
housing.
4. Tighten the packing nut (221) just enough to stop
leakage, but no tighter. Fill the wet–cup/packing nut
1/3 full with Graco TSL.
62
FACE OF
BEARING
HOUSING
Fig 36–2
Disassembling the Pump
1. Unscrew the intake valve (222) from the cylinder
(216). Remove the gasket (206*), ball guide (215),
stop pin (207*) and ball (204*) from the valve. Clean
and inspect the parts for wear or damage, replacing
parts as needed. Always use a new gasket (206*),
provided in the repair kit.
2. Unscrew and remove the packing nut (221) and
plug (201).
3. Use a plastic mallet to tap the piston rod down . Pull
the rod out through the bottom of the cylinder.
4. Remove the throat packings (218) and glands
(211, 212).
5. Clamp the flats of the piston rod in a vise. Use a 7/8
in. wrench to loosen the retaining nut (214), and then
to unscrew the piston valve (224) from the rod.
6. Remove the backup washer (219), seal (205), pack-
ings (217) and glands (213,220).
63
63
64
62
65
TORQUE TO
70 ft–lb
(95 N.M)
Refer to Fig 36–1.