820-204
23
Displacement Pump
118
*119
*121
*122
120
107
18
17
21
20
33
32
36
38
27
13
Fig. 17
1
2
Apply pipe
sealant (42e)
2
1
85
03200A
Torque to
50 ft–lb (68 N.m)
820–206 shown
17
18
123
15
Fig. 18
21
102
Torque to
50 ft–lb (68 N.m)
01068
1
1
Intake valve repair (See Fig. 17)
1.
Remove the suction hose or tube. See Step 4 and
5, Removing the pump.
2.
Unscrew the intake valve (118). Remove the
o-ring (119*), ball guide (120), stop pin (122*) and
ball (121*) from the valve.
3.
Clean and inspect the parts for wear or damage.
Replace parts as needed. Use a new o–ring
(119*). If no further service is needed, reassemble
the pump.
Disassembling the pump (See Fig. 19)
1.
Remove the intake valve (118).
2.
Loosen the packing nut (102) and plug (123).
3.
Use a plastic mallet to tap the piston rod (107)
down, and then pull the rod out through the bottom
of the cylinder.
4.
Remove the packing nut (102) and throat
packings.
5.
Loosen the jam nut (117). Remove the cylinder
(115) and the o-ring (116*).
6.
Clamp the flats of the piston rod in a smooth jaw
vise. Use an open-end wrench to loosen the nut
(110) and then unscrew the piston valve (108).
7.
Remove all parts from the piston valve (108).
Reassembling the pump
CAUTION
Incorrect installation of the packings damages the
packings and causes pump leaks.
NOTE: Alternate the plastic and leather packings. See
Fig. 19. The lips of the throat V-packings face down.
The lips of the piston V-packings face up. The lips of
seal (125*) face down.
NOTE: Soak the leather packings in oil before reas-
sembling the pump.
1.
Check the outside of the piston rod (107) and the
inside of the cylinder (115) for wear. Replace worn
parts to ensure a good seal with the new packings.
2.
Stack these parts onto the piston valve (108) one
at a time: the backup washer (126*) and u–cup
(125*), the female gland (114*), alternately three
plastic (112*) with two leather packings (113*),
and the male gland (111*). See Fig. 20.
3.
Tighten the nut (110) onto the piston valve (108) to
2 in-lb (0.23 N.m). See Fig. 21.
Note the alignment of the piston (108) to the nut
(110). Maintain this alignment through Step 8.
4.
Clean all residue from the piston valve threads.
Apply one strip of adhesive, supplied, to the
threads.
5.
Place the ball (109*) on the piston valve (108). See
Fig. 20.
