Graco 218334, Instructions Manual

Page: 11 / 20

Maintenance and Repair
307714E 11
Air Motor Assembly
Reference numbers used in the following instructions
refer to F
IG
. 4 on page 10.
1. Install the piston o-ring (69) on the piston (44) using
heavy petroleum grease. Be sure the slots in the
gasket (103) align with the air passages in the motor
cylinder (104). Since the diameter of the o-ring is
greater than the piston, gather the excess o-ring to
one side of the piston and tuck it into one of the two
indented areas of the air motor cylinder.
2. Secure the cylinder (104) with the eight screws
(105) and washers (68). Torque to 25 ft-lbs (34
N.m).
3. Be sure the back-up washer (99) and v-packing (71)
are in place on the trip rod bearing (98).
4. Place the copper gasket (100) over the trip rod (43a)
and attach trip rod bearing (98) to the trip rod.
5. Reinstall the dampening pad (97) and thrust washer
(96).
6. Place the valve plate seals (42) between the air
manifold (87) and the valve plates (101) with the
rounded side of the valve plates out. Screw four
manifold plate screws (88) into both air manifolds.
7. Before installing the air manifolds (87) pull the trip
rod and piston assembly up as far as possible. Line
up the air manifolds with the gaskets (91) and
loosely screw the two rear manifold screws (85) with
lockwashers (86) into both air manifolds.
8. Position the alignment tool (see Accessories page
X) between the two air manifolds. Hold the two air
manifolds against the alignment tool and torque the
screw (85) in each manifold to 25 ft. lbs (34 N.m).
Screw another screw into each manifold. Remove
the alignment tool.
NOTE: If an alignment tool is not available, com-
plete the following steps 9 & 10. Then measure and
set the space at 1.8 inch (45.7 mm) between the two
air manifolds and the air valve housing (102).
9. Screw the trip rod bushing (95) onto the trip rod
(43a). Hold the trip rod with padded pliers.
NOTE: Special care to avoid damaging the plated
surface of the trip rod must be taken. A padded pli-
ers, part number 207579 is available from Graco.
10. Place the air valve housing (102) over the trip rod
bushing (95).
11. Secure the air valve house (102) with the trip rod nut
(106) and lockwasher (86). Torque the nut to 20-25
ft-lbs (27-34 N.m) until .031 in. (about the thickness
of a US dime) of the trip rod (43a) extends above
the nut.
12. Place the o-rings (93) around each director valve
(92).
13. Place the two compression springs (94) in each side
of the air valve housing (102).
14. With the air valve housing (102) pushed all the way
down against the air motor cylinder (104), place the
air director valves (92) against the springs (94) and
compress them into the air valve housing (102).
15. Install the dampening rod (97) and thrust washer
(96) in the detent housing (91). Use a heavy petro-
leum base grease to hold them in position.
16. Coat the plungers (80), spring guides (79), and
compression springs (78) with heavy petroleum
grease and install them in the detent housing.
17. Engage the threads of the detent spring retainers
(77) one turn into the detent housing (81).
18. Place the detent axle (90) and roller (89) into the
detent housing (81), using heave petroleum grease.
19. Place the detent housing (81) on the air manifolds
(87) while holding the detent axles (90) and rollers
(89) in position with your fingers from the top of the
housing.
20. Before install the four detent housing screws (82)
and lockwashers (83), be sure the detent axles (90)
and rollers (89) align correctly with the valve hous-
ing (102). Tighten the detent spring retainers (77) as
required to properly align the rollers (89).
21. Screw the four detent housing screws (82) with lock-
washers (83) into the housing (81).
22. Position the spring cap (107) on the air manifold.
23. Place the air motor shield (73) over the air motor
and secure it with the eight shield retaining screws
(75).
24. Reinstall the swivel adapter (117). Screw in the lift
ring (74).