Technical data

308-248 21
Displacement Pump Repair
WARNING
INJECTION HAZARD
T o reduce the risk of serious injury ,
whenever you are instructed to relieve
pressure, follow the Pressure Relief
Procedure on page 9.
NOTE: Packing Repair Kit 235–703 is available.
Reference numbers of parts included in the kit are
marked with an asterisk, i.e., (121*). For the best
results, use all the new parts in the kit, even if the old
ones still look good.
NOTE: T o minimize down time, and for the best sprayer
performance, check the motor brushes (see page 19)
and clean the transducer (see page 30) whenever you
repack
the pump. Replace these parts as needed.
Removing the pump (See Fig. 16.)
1. Flush the pump, if possible. Relieve pressure. Stop
the pump with the piston rod (107) in its lowest
position, if possible. T o lower the piston rod manu -
ally
, rotate the motor fan blades.
2. Remove the filter (85).
3. Remove suction hose or tube (32).(For suction
hose, refer to page 31.
NOTE: If repairing only the intake valve assembly , go
to
Intake valve repair , page 22.
4. Use a screwdriver to push the retaining spring (18)
up and push out the pin (17).
5. Loosen the screws (21). Remove the pump (20).
Installing the pump (See Fig. 16 and 17.)
1. Mount the pump on the drive housing. T ap it into
the alignment pins with a soft hammer . T ighten the
screws (21) to 50 ft-lb (68 N.m).
WARNING
MOVING P ARTS HAZARD
Be sure the retaining spring (18) is firmly
in the groove all the way around, to pre -
vent the pin (17) from working loose due
to vibration. See Fig. 17.
If the pin works loose, it or other parts could break
of f due to the force of the pump action. These parts
could be projected into the air and result in serious
injury or property damage, including the pump
connecting rod or drive housing.
2. Align the hole in the rod (107) with the connecting
rod assembly (15). Use a screwdriver to push the
retaining spring (18) up and push in the pin (17).
Push the retaining spring (18) into place around
the connecting rod.
3. Replace the o-ring (27) if it is worn or damaged.
Reconnect the suction and drain hoses (32,33).
Install the front cover (13).
4. T ighten the packing nut (102) just enough to stop
leakage, but no tighter . Fill the packing nut/wet-cup
1/3 full with Graco TSL. Push the plug (123) into
the wet-cup.
Fig. 16
1
2
Torque
to
50 ft–lb (68 N.m)
Apply sealant (42d)
118
*119
*121
*122
120
17
18
20
2
33
32
38
21
1
13
107
02832
36
Model
231–208 Shown
27
85
Fig. 17
17
18
123
15
102
1
Torque
to
50 ft–lb (68 N.m)
1
04655
21