16
820-007
Displacement Pump
WARNING
To reduce the risk of serious injury, always follow
the Pressure Relief Procedure Warning on page
4 before continuing.
Removing the Pump
1.
Flush the sprayer if possible.
2.
Remove the hose clamps (87, 88) and move the
drain tube (90) away from the pump. Unscrew and
remove the suction tube (52). Remove the adapter
(50). See Fig. 6.
3.
Disconnect the hose (20) from the nipple (22). See
Fig. 6.
4.
Push the retaining spring (55) up. Push out the pin
(57).
5.
Loosen the cylinder locknut (103) and unscrew the
pump (26) from the drive assembly (65).
6.
See Disassembling the Pump, below.
Installing the Pump
1.
To reinstall the pump, rotate the crankshaft so that
the connecting rod (64) is in its lowest position.
Pull the pump piston rod (47) about 1–1/2 inches
out of the cylinder (46), and turn the rod so the pin
hole is about 90
from the outlet nipple (22).
Screw the cylinder locknut (103) all the way down.
2.
Screw the pump (26) into the drive assembly (65)
until the holes in the piston rod and the connecting
rod are aligned. Insert the pin (57) and push the
retaining spring (55) down over the pin.
3.
Screw the pump cylinder
completely into the drive
assembly; you will feel some resistance from the
packings. Now turn the cylinder back until the out-
let nipple (22) faces back. Screw the hose (20)
onto the nipple; tighten it securely. To avoid having
the cylinder locknut (103) loosen due to vibration,
tighten the locknut up against the drive housing to
70 ft–lb (95 N.m).
4.
Reassemble remaining parts reverse from disas-
sembly.
NOTE: Use Repair Kit No. 820–549 to repair the
pump. See page 27. Use all the parts in the kit, even if
the old ones look good. Old and new parts do not seal
together well, and the pump may leak.
Disassembling the Pump
1.
Remove the pump from the sprayer as described
above.
2.
Unscrew the intake valve (48) from the cylinder
(46). If the valve is seized in the housing, squirt
penetrating oil around the threads and gently tap
around the housing with a light hammer to loosen.
See Fig. 7 and 9. Remove the ball guide (40), the
stop pin (39) and the ball (28). Clean and inspect
the parts for wear or damage.
NOTE: Test the intake valve by filling it with solvent
and seeing if any solvent leaks past the ball. It
shouldn’t leak. The valve must be clean for this test;
any dirt will hold the ball off the seat and let the solvent
leak past.
Fig. 6
88
87
90
65
55
64
57
20
22
26
52
47
50
103
Torque to
70 ft–lb
(95 N.m)
Fig. 7
46
28
40
41
48
39
0742
Summary of Contents for 820-001
Page 3: ...3 820 007 Notes...
