Graco HydroShield WABH00 Instructions - Parts Manual page 103

5. Disassemble the air section of the pump:
a. Loosen the four tie rod screws (312) with a
socket wrench and remove.
b. Remove the air cover (320) and o-ring (318).
Inspect the o-ring and replace if the pump
has been leaking air.
c. Wiggle the air cylinder (319) off of the middle
housing (307).
Figure 47 Removing the Air Cover
6. To service the fluid piston (301):
a. Pry or pick the seal (302) off from the back
side of the fluid piston (301) so that the front
face of the piston is not damaged. If the front
face is damaged, it may not seal completely.
b. Replace the seal on the fluid piston (301).
3A8492A
7. To service the air piston (316):
a. Remove the o-ring (317) from the air piston
(316).
b. Apply grease to the o-ring before replacing.
8. To remove the piston rod (305):
a. On the fluid side, use a 12 inch adjustable
wrench on the flats of the piston rod, near
the fluid piston (301).
b. Use a 15 inch adjustable wrench on the flats
of the fluid piston (301) to loosen.
c. Unscrew the fluid piston (301) off of the
piston rod (305).
d. Push the piston rod (305) through the middle
housing (307) to remove.
9. To remove the air piston (316) from the piston
rod (305):
a. Use 12 inch wrench on the flats of the piston
rod, near the air piston (316).
b. Use a 15 inch adjustable wrench on the flats
of the air piston (316) to loosen.
c. Unscrew the air piston (316) off of the piston
rod (305). Under the air piston is an o-ring
(315), magnet holder (313), and magnet
(314).
10. If necessary, remove the piston bumpers (308)
on each side of the middle housing. Push in one
of the three tabs to pop off. The bumpers snap in.
Repair
103