Graco 25T471, Manual

Page: 19 / 28

Repair
3A7931B 19
Repair
Disassembly
NOTE: Reference numbers in parentheses in the text
refer to the callouts in section Parts on page 22. Refer
to those for service.
1. Follow the Pressure Relief Procedure on page 12.
2. Disconnect all hoses. Remove the wiper plate.
Remove the fluid outlet fitting, noting its position rel-
ative to the air inlet. Remove only the three screws
and lock washers holding the pump to the mounting
bracket.
3. Remove fluid outlet fitting and pump bleeder valve,
then lift the pump straight up through the bracket.
4. Remove the pin (212) from the fluid piston (201).
Unscrew the air motor shaft from the fluid piston
(201) by turning the screw (227).
5. Unscrew the adapter (224) from the cylinder cou-
pling (223). Pull the air motor coupling straight up
until it clears the fluid piston (201).
6. Hold the fluid piston (201) steady by inserting a
small screwdriver or punch into the 4 mm diameter
hole (BA). Remove the screw (213) and lock washer
(211) holding the priming piston (208) to the priming
piston rod (204).
7. Pull the priming piston rod (204) and fluid piston
(201) straight up out of the fluid housing (203).
Remove the pin (210), and unscrew the priming pis-
ton rod (204) from the fluid piston (201).
8. Unscrew the pump fluid intake housing (205) from
the fluid housing (203). Remove the o-ring (214)
from the intake valve housing (205).
9. Remove the intake valve (207) and valve stop (206)
from the pump fluid intake housing (205).
10. Unscrew the wet-cup/packing nut. Remove the
u-cup packing (215) from the throat. Remove the
washer (216) from the wet-cup/packing nut.
11. Unscrew the piston rod housing (232). Remove the
u-cup packing (215) from the fluid housing (203).
12. Clean all parts with a solvent compatible with the
fluid you are pumping, and inspect for wear or dam-
age.
Air Motor
1. Use a 10 mm socket wrench to remove four screws
(411). Remove the air valve (414) and gasket (409).
2. Remove four screws (411) and remove the manifold
(420) and two gaskets (408).
3. Use a 10 mm socket wrench to remove the pilot
valves (413) from the top and bottom cover.
4. Use a 13 mm socket wrench to remove the tie bolts
(412).
5. Remove the top cover (410). Remove the o-ring
(402). On 3.5 in. motors only, remove the plug (431)
and o-ring (430).
6. Remove the shield (406) and cylinder (405).
7. Remove the o-ring (404) from the piston.
8. Secure the piston (419) in a vise with soft jaws. Use
a wrench on the flats of the rod (418) to remove the
rod and bottom cover assembly (401) from the pis-
ton.
9. Remove the rod from the bottom cover assembly.
10. Remove retaining ring (417), u-cup seals (407), and
o-ring (402) from the bottom cover.