308608K 13
Air Motor and Throat Service
12. Grease and reinstall the u-cup seal (10
{
), thread
the throat bearing (36) into the air motor base (28),
and torque the throat bearing to 30 to 40 ft-lb
(41 to 54 N.m) using a 2-in. socket.
13. Slide the piston rod (29) down through the pack-
ing, and lower the piston assembly (27) into the air
motor base (28).
14. Carefully lower the cylinder (30) straight down onto
the piston assembly (27). Tighten the eight screws
(3) holding the cylinder to the base (28).
CAUTION
To avoid damaging the cylinder wall, lower the
cylinder straight down onto the piston. Never tilt
the cylinder as it is being lowered.
15. Grip the trip rod (31) with padded pliers, screw the
lift ring (24) onto the trip rod, push the lift ring
down, and screw it into the top of the cylinder.
16. Install the u-cup packing (107
{
) with the lips up,
and place the piston washer (113) on the piston/
valve seat (109). Make sure the lips of the u-cup
packing face up. See Fig. 3.
17. Place the piston ball (103) in the piston rod (29).
18. Clean the threads of the piston/valve seat, Apply
Loctite
r
to the threads, (109), and thread the
assembly from Step 16 onto the piston rod (29).
19. Clamp the flats of the piston/valve seat (109) in a
vice, and torque the piston rod (29) to the piston
valve seat to 40 to 60 ft-lb (54 to 81 N.m).
20. Clamp the air motor base (28) in a vise horizontally
by closing the vice jaws on the flange
21. Use a strap wrench to screw the displacement
pump cylinder (110) to the air motor base (28), and
torque to 95 to 105 ft-lb (129 to 142 N.m).
22. Before remounting the pump, connect an air hose
and run the air motor slowly, starting with just
enough air pressure to make the air motor run, and
make sure that it operates smoothly.
23. Reconnect the ground wire before regular opera-
tion of the pump.
