8
308127
Displacement Pump Repair
WARNING
Before doing this procedure, follow the
Pressure
Relief Procedure Warning on page 2 to reduce
the risk of serious bodily injury.
Disassembly Procedure
12. Relieve pressure. See page 2. Remove the pump
from the sprayer. See page 5.
13. Disassemble the intake valve. See Fig 5.
14. Clean and inspect the parts. Replace worn or dam-
aged parts. Use a new o–ring (1*). If no further
service is needed, reassemble the intake as
shown in Fig 5.
15. To disassemble the rest of the pump, remove the
packing nut (16) and plug (5). Tap the piston rod
(24) down with a plastic mallet. Pull the rod out
through the bottom of the cylinder. See Fig 10.
16. Remove the throat packings. See Fig 10.
WARNING
Always use the special sleeve removal tool, P/N
220991, to remove the sleeve. Other tools may
cause the pump to rupture, resulting in serious
bodily injury. If the sleeve cannot be removed easi-
ly using the tool, return the sleeve and cylinder to
your Graco distributor for removal.
17. To remove the sleeve, screw the tool’s large nut
(B) into the top of the cylinder (19). Screw down
the rod (A) to push the sleeve out. See Fig 6. Re-
move the tool.
18. Clamp the flats of the piston rod (24) in a vise.
Loosen the retaining nut (11). Unscrew the piston
valve (22) and disassemble its parts. See Fig 7.
Reassembly Notes
A. Pump Repair Kit, 220877, is available. For the best
results, use all the new parts in the kit. The kit
parts are shown with an asterisk (10*) in the text
and drawings.
B. Check the outside of the piston rod (24) and the
inside of the sleeve (18) for scoring or scratches. If
the parts are damaged, new packings will not seal
properly. Replace these parts if needed.
C. Alternate leather and poly packings as shown in
Fig 10. The lips of the throat “V” packings must
face down. The lips of the piston “V” packings
must face up. The lips of the U–cup seal (3) face
down. Incorrect installation damages the packings
and causes the pump to leak.
D. Soak leather packings in oil.
Fig 5
*1
4*
23
19
20
*21
Torque to
110 ft–lb
(146 N.m)
1
02560
Fig 6
19
B
A
0028B
Reassembly Procedure
19. Stack these parts on the piston valve (22): washer
(14), seal (3*), female gland (15*), alternate the
packings (12*, 6*), male gland (10*). See Fig 7.
20. Tighten the packing retaining nut (11) onto the pis-
ton valve (22) to the torque specified in Fig 7.
21. Put the ball (25*) on the piston valve. See Fig 7.
CAUTION
Follow Steps, 4, 5, and 6 carefully to avoid damag-
ing the packings by overtightening.
22. Apply one drop of adhesive, supplied, to the piston
valve threads. Hand tighten the valve into the pis-
ton rod just until the nut (11) contacts the rod. See
Fig 7.
23.
Note the alignment of the piston (22) to the nut
(11). Maintain this alignment through Steps 5, 6
and 7.
24. Place the flats at the top of the rod (24) in a vise.
Apply one drop
of sealant to
these threads
Torque to
4 in-lb (0.35 N.m)
11
Fig 7
22
10*
3*
15*
25*
24
0029
*14
1
3
4
2
Lips must face up
*6
*12
2
3
4
Lips must face down
1
