Graco 223843, Instructions Manual

Page: 14 / 24

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Displacement Pump Service
Disassembly
When disassembling the pump, lay out all removed
parts in sequence, to ease reassembly. Refer to Fig 4.
NOTE: Repair Kit 235635 is available. For the best
results, use all the new parts in the kit. Parts included
in the kit are denoted with one asterisk, for example
(6*).
Clean all the parts thoroughly when disassembling.
Check them carefully for damage or wear, replacing
parts as needed.
1. Remove the displacement pump from the air motor
as explained on page 13.
2. Unscrew the intake valve housing (1) from the
outlet housing (3). If it is difficult to remove, squirt
penetrating oil around the threads and gently tap
around the valve housing with a plastic hammer to
loosen it. See Fig 4.
3. Remove the ball stop pin (14), o--ring retainer (16),
o--ring (15), guide (22) and ball (7) from the intake
valve housing (1).
4. Loosen the packing nut (4). Push the displacement
rod (19) down as far as possible, then pull it out
the bottom of the outlet housing (3).
5. Secure the flats of the piston stud (2) in a vise.
Using a wrench on the flats of the displacement
rod (19), screw the rod off the piston. Remove the
ball (6), retainer (12), packings (8, 13) and glands
(17, 18).
6. Remove the packing nut (4), throat packings (8,
13) and glands (17, 18) from the outlet housing (3).
7. Inspect all parts for damage. Clean all parts and
threads with a compatible solvent before reassem-
bling. Inspect the polished surfaces of the dis-
placement rod (19) and sleeve (10) for scratches,
scoring or other damage, which can cause prema-
ture packing wear and leaking. To check, run a
finger over the surface or hold the part up to the
light at an angle. Be sure the ball seats of the
piston (2) and intake valve housing (1) are not
chipped or nicked. Replace any worn or damaged
parts.
NOTE: If the sleeve (10) needs replacement and is
hard to remove, contact your Graco distributor.
Reassembly
1. Lubricate the throat packings and install them in
the outlet housing (3) one at a time as follows, with
the lips of the v--packings facing down: the male
gland (17*), one PTFE v--packing (13*), two leath-
er v--packings (8*), one PTFE (13*), one leather
(8*), one PTFE (13*), and the female gland (18*).
Install the packing nut (4) loosely. See Fig 4.
2. If you removed the sleeve (10), reinstall it in the
outlet housing (3), making sure to replace the
gasket (9*).
Be sure the tapered end of the sleeve
faces down, toward the pump intake.
3. Lubricate the piston packings and install them onto
the piston stud (2) one at a time in the following
order,
with the lips of the v--packings facing up: the
female gland (18*), one PTFE v--packing (13*), two
leather v--packings (8*), one PTFE (13*), one
leather (8*), one PTFE (13*), the male gland (17*),
and the packing retainer (12). See Fig 4.
4. DO NOT use thread sealant on the piston stud.
Install the piston ball (6*) on the piston and screw
the piston valve assembly into the displacement
rod (19). Torque to 65--75 ft--lb (88--102 N.m).
5. Insert the displacement rod (19) into the bottom of
the outlet housing (3), being careful not to scratch
the sleeve (10). Push the rod straight up until it
protrudes from the packing nut (4).
6. Install the ball (7*), guide (22), o--ring (15*), retain-
er (16), and ball stop pin (14) in the intake valve
housing (1). Screw the intake housing into the
outlet housing (3). Torque to 75--100 ft--lb
(102--136 N.m).
7. Reconnect the displacement pump to the air motor
as explained on page 13.