Displacement Pump Service - Graco Fire-Ball 203872 Instructions-Parts List Manual

Displacement Pump Service

Before You Start
Be sure you have all necessary parts on hand. Pump
Repair Kit 238286 includes repair parts for the pump
and air motor. Use all the parts in the kit for the best
results. Parts included in the kit are marked with one
asterisk, for example (12*), in the text and drawings.
See the Air Motor Parts List on page 16 and the
Pump Parts List on page 17.
1. Flush the pump, and relieve the pressure.
WARNING
To reduce the risk of serious injury whenever you
are instructed to relieve pressure, always follow the
Pressure Relief Procedure on page 8.
2. Disconnect the hoses, remove the pump from its
mounting, and clamp the air motor base in a vise
horizontally by closing the vice jaws on the flange.
3. Unscrew the intake valve body (107) from the fluid
cylinder (105). Disassemble the intake valve (see
the Parts Drawing). Clean and inspect the parts
for wear or damage, and replace parts as needed.
Be sure to check the o-ring (108*). Unless further
intake valve service is needed, reassemble and
reinstall, using liquid sealant on the male threads.
4. Use a strap wrench on the fluid cylinder (105) to
screw it out of the air motor base (5). Carefully
inspect the smooth inner surface of the cylinder for
scoring or irregular surfaces. Such damage
causes premature packing wear and leaking, so
replace the part if it is damaged.
5. Using wrenches on the flats of the displacement
rod (8) and on the flats of the fluid piston (110),
unscrew the fluid piston from the displacement rod.
6. Take the ball (111) out of the displacement rod (8),
and take the packing o-ring (104*) off of the fluid
piston (110).
7. Clean and inspect the parts. Use all the repair kit
parts during reassembly, and replace other parts
as necessary.
8. Place the piston ball (109) in the displacement rod
(8).
9. Install the new packing o-ring (104*) on the fluid
piston (110).
10. Clamp the flats of the fluid piston (110) in a vice,
and torque the displacement rod (8) to the piston
to 40 to 60 ft-lb (54 to 81 N.m).
11. Clamp the air motor base (5) in a vise horizontally
by closing the vice jaws on the flange.
12. Use a strap wrench to screw the displacement
pump cylinder (105) to the air motor base (5), and
torque to 95 to 105 ft-lb (129 to 142 N.m).
13. If you disconnected the ground wire, reconnect it
before you resume regular pump operation.
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