Displacement Pump Repair
WARNING
INJECTION HAZARD
To 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. Refer-
ence 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: To minimize down time, and for the best sprayer
performance, check the motor brushes (see page 20)
and clean the transducer (see page 31) whenever you re-
pack the pump. Replace these parts as needed.
Removing the pump
(See Fig. 17.)
1.
Flush the pump, if possible. Relieve pressure. Stop
the pump with the piston rod (107) in its lowest
position, if possible. To lower the piston rod manu-
ally, rotate the motor fan blades.
2.
Loosen the swivel nut on adapter (38) and remove
suction hose (32). While pushing in on the collar of
elbow (36), pull out and remove drain tube (33).
NOTE: If repairing only the intake valve assembly, go
to Intake valve repair, page 23.
3.
Use a screwdriver to push the retaining spring (18)
up and push out the pin (17).
4.
Loosen the screws (21). Remove the pump (20).
Installing the pump
(See Fig. 18 and 19.)
1.
Mount the pump on the drive housing. Tap it into
the alignment pins with a soft hammer. Tighten the
screws (21) to 50 ft-lb (68 N.m).
WARNING
MOVING PARTS 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. 18.
If the pin works loose, it or other parts could break
off 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 con-
necting 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.
Reconnect the suction and drain hoses (32,33).
Install the front cover (13).
4.
Tighten 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. 17
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
04654
36
Fig. 18
17
18
123
15
102
1
Torque to
50 ft–lb (68 N.m)
1
04655
21
