Graco B Series Instructions-Parts List Manual page 14

Air Motor and Throat Service
Reassembly
1. Clean all the parts carefully in a compatible
solvent, and inspect for wear or damage. Use all
the repair kit parts during reassembly, and replace
other parts as necessary.
2. Check the polished surfaces of the piston (2),
displacement rod (8), and cylinder (17) wall for
scratches or wear. A scored rod causes premature
throat seal wear and leaking.
3. Lubricate all parts with a light, water-resistant
grease.
4. Install the new throat seal (6), lips facing down.
Screw the packing nut (38) into the base (5).
5. Slide the displacement rod (8) down through the
throat, and lower the piston (2) into the base (5).
Be sure the o-rings (9, 10, and 24) are in place.
See Fig. 4.
6. Pull the exhaust valve poppets (16) into the valve
actuator (13), and clip off the top part shown with
dotted lines in Fig. 5.
L 2
26 27 25
1
M
14
1
Turn wires up.
2
Push toggles (L) in and then up.
3
Cut off tops of poppets as indicated by dotted lines.
Fig. 5
14 308883
11 22
04118
16
7. Install the transfer valve grommets (12), and
reassemble the valve mechanism. Before you
install the lockwires (31) in the adjusting nuts (30),
use the special gauge, 171818, to adjust the
transfer valve so there is 0.145 in. (3.7 mm)
clearance between the poppets (1b) and the seat
when it is open. See Fig. 5. Snap the toggles (25)
to the up position.
8. Reassemble the air motor, and assemble to the
displacement pump. Torque the extension tube
(64) to to base (5) at 45 to 55 ft-lb (61 to 75 N-m).
Before you install the air motor plate, tighten the
throat packing nut (38) snugly; do not overtighten
it.
9. Before you remount the pump, connect an air
hose, and run the pump slowly, at about 40 psi
(276 kPa, 2.8 bar), to see that it operates
smoothly.
10. Reconnect the ground wire before regular
operation of the pump.
14
13
31
30
1b
12
30
1b
2
11
3
1a
16
Cutaway View
04119
30
12
30
24
0.145 in.
(3.7 mm)
1b
2