Graco EM 380 Instructions-Parts List Manual page 5

Unscrew and remove packing nut (70). Using a rubber
mallet, tap piston rod (79) down and pull out through
bottom ofcylinder (78). See Fig 3 and 4.
Remove glands (66 Et 69) and packings (67 & 68).
Clean and inspect piston rod and inside of cylinder for
nicks, scratches or scoring which could cause leaking or
premature wear of packings.
Clamp flats of piston rod in a vise. Use a large
screwdriver to unscrew adapter (76) from valve (81).
Remove seal (61) and washers (77). See Fig 3 and 4.
Use a wrench to loosen nut (65) and unscrew valve (81)
from piston rod. Remove ball (59). Remove nut, glands
(62 Et 64) and packings (63 Et 75).
-
0
&b-
76
80
Assembling Pump
When assembling pump, coat packings, piston rod and
inside of cylinder with hydraulic oil.
When reassembling piston, install new glands and pack-
ings in correct order, alternating leather and plastic
packings. See Fig 3. "V" of packings must face up
against fluid pressure. See Fig 4. Tighten nut (65) to
10.5 in-lb (1.2 N-m) to seat packings, then back off and
tighten hand tight.
Place new ball in piston rod (79). Apply locking com-
pound to threads of valve (81) and screw it into rod. Us-
ing a torque wrench on nut (65) and a screwdriver on
valve (811, tighten nut against piston rod to 18-29 ft-lb
(24-27 N.m) torque, without changing the tightness of
the nut against packings.
Install new seal and washers on adapter (76) and screw
into valve (81).
Install throat packings, glands and packing nut, leaving
packing nut loose. "V" of packings must face down
against fluid pressure. Put plastic packing (68) on top of
leather packings.
Insert piston rod through bottom of pump cylinder.
Assemble and install intake valve and tighten packing
nut
just
enough to stop leakage - no tighter.
d!v-
81
Fig 3
I
l-
"V" FACES
DOWN
I
AGAINST
PRESSURE
78
"V" FACES
UP AGAINST
PRESSURE
'1 1 /-"l;'l',"CES
i(I
AGAINST
PRESSURE
Fig 4
307464 5