Graco EM 490 Instructions-Parts List Manual page 20

Reassembly Notes
A. Packing Repair Kit 222–587 is available. Parts in-
cluded in the kit are marked with an asterisk (*) in the
text and drawings.
B. Clean all parts thoroughly. Check the outside of the
piston rod (224) and the inside of the sleeve (218) for
scoring or scratches, which prevent the packings
from sealing properly. Replace all worn parts.
C. Alternate polyethylene and leather packings as
shown in Fig 27. Notice that:
the lips of the throat v–packings face down;
the lips of the piston V–packings face up;
the lips of the U–cup seal (203*) face down. Incorrect
installation damages the packings and results in
pump leakage.
D. Coat the piston rod and the inside of the cylinder with
lightweight oil, and soak the packings in the oil, before
reassembling.
Reassembly Procedure
1 Stack the backup washer (214*), U–cup seal (203*)
lips down , and female gland (215*), alternate the
polyethylene and leather v–packings (212*, 206*) lips
up, and stack the male gland (210*) onto the piston
valve (222). See Fig 27.
2 Tighten the packing retaining nut (21
piston valve (222) and torque to 0.7 N.m (6
See Fig 24.
NOTE: NOTE THE ALIGNMENT of the piston (222) to
the nut (211). Maintain this alignment throughout
Steps 2, 3 and 4.
211
TORQUE NUT TO
0.7 N.m
(6 IN-LB)
Fig 24
Apply 1 drop only of sealant, supplied with the repair
3
kit, to the piston valve threads. Place the small ball
(201*) on the valve. See Fig 24. Hand tighten the
valve into the rod (224) just until the nut contacts the
rod. Place the flats of the displacement rod in a vise.
DISPLACEMENT PUMP
1) onto the
in–lb).
201*
APPLY ONE DROP
OF SEALANT TO
THESE THREADS
NOTE AND MAINTAIN
THIS ALIGNMENT
THROUGHOUT STEPS
2,3, and 4
222
0082
211
TORQUE NUT
AGAINST ROD TO
25 N.m (19 FT-LB)
Fig 25
4 Torque the nut (211) against the rod (224) to 25 N.m
(19 ft–lb). Use two wrenches to maintain the align-
ment as mentioned in the NOTE. See Fig 25.
5 Stack the male gland (208*), alternate the polyethyl-
ene and leather v–packings (213*, 207*) lips down
and stack the female gland (209*) one at a time into
the top of the cylinder. See Fig 27.
6 Loosely install the packing nut (216) and plug (205).
7 Place a new o–ring (202*) firmly in the cylinder
groove. See Fig 27.
8 Coat the piston rod and packings with oil. Carefully
slide the assembly
SLEEVE.
And then slide the sleeve/piston rod assembly INTO
THE BOTTOM OF THE CYLINDER. This procedure
helps prevent damaging the packings during reas-
sembly. See Fig 26.
NOTE: The tapered end of the sleeve is the bottom of it.
Do not install it upside down. See Fig 26.
PISTON
ASSEMBLY
Fig 26
9 Assemble the intake valve. Use a new gasket (202*).
Screw the valve into the cylinder and tighten to 64
N.m (48 ft–lb). See Fig 27.
10 Screw down the cylinder locknut (112) until it is finger
tight at the bottom of the external cylinder threads.
See Fig 27.
11 Install the displacement pump on the sprayer . See
page 19.
224
INT O THE T OP OF THE
CYLINDER
SLEEVE
TAPERED END
0083
0084