16
308–030
DISPLACEMENT PUMP
To reduce the risk of serious bodily injury,fol-
low the Pressure Relief Procedure Warning
on page 14 before checking or repairing any
part of the spray system.
WARNING
Removing the Pump. See Fig 11.
NOTE: Refer to Fig 11 for this procedure.
1. Flush the sprayer. Relieve pressure.
2. Hold the intake valve (222) steady with a
wrench and unscrew the swivel union (12).
3. Unscrew the hose (26).
4. Use a screwdriver to push the retaining spring
(65) aside, and then push out the pin (63).
5. Loosen the locknut (31) and unscrew the
pump (29).
Fig 11
222
*206
*204
*207
215
26
12
63
65
29
223
A
64
8
30
31
TORQUE TO
70 ft–lb
(95 N.m)
Reinstalling the Pump. See Fig 11.
1. Rotate the crankshaft (A) so the connecting
rod (64) is in its lowest position. (Rotate the
fan blades at the rear of the motor with a
screwdriver.) The pump piston rod (223)
should protrude about 1 in. (25 mm) above the
pump cylinder. Screw the pump into the pump
coupling (64) until the pin holes are aligned.
Insert the pin (63). Position the spring (65) so
it covers the ends of the pin. Screw the pump
into the drive housing (8) until it stops at the
locknut (31). Unscrew the pump just until the
fitting (30) faces straight back.
Be sure the retaining spring (65) is firmly and
completely in the groove of the connecting
rod to prevent the pin (63) from working loose
due to vibration. See Fig 11.
If the pin works loose, it or other parts could
break off due to the force of the pumping ac-
tion. These parts could be projected through
the air and result in serious bodily injury or
property damage, including damage to the
pump, connecting rod or bearing housing.
WARNING
2. Torque the locknut (31) to 70 ft–lb (95 N.m).
3. Reassemble the remaining parts, in the re-
verse order of removal.
Disassembly. See Fig 14, except where noted.
1. Remove and disassemble the intake valve
(222). If no further service is needed, rea-
semble the valve, using a new gasket (206).
Torque to 80 ft–lb (107 N.m). See Fig 11.
2. Remove the packing nut (221) and plug (201).
3. Tap the piston rod (223) down with a plastic
mallet. Pull the rod out the bottom of the cylin-
der (216).
4. Remove the packings and glands from the
throat of the cylinder (216).
5. Clamp the flats of the piston rod (223) in a
vise. Unscrew the retaining nut (214). Un-
screw the piston valve (224) from the rod. Re-
move all parts from the piston.
Reassembly Notes
A. Packing Repair Kit 222–587 is available. Parts
included 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 (223) and the inside of the
cylinder (216) 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 14. 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 (205) face down.
Incorrect installation damages the packings
and results in pump leakage.
D. Coat the piston rod and the inside of the cylin-
der with lightweight oil, and soak the packings
in the oil, before reassembling.
Summary of Contents for PRO 301
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