7221A

Air Motor and Throat Service

12.Grease and reinstall the seal (2*) with the lips down, 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 1 5/8-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) that hold the cylinder to the base (28).

CAUTION

To avoid damaging the cylinder wall, lower the cylinder straight down onto the piston. Do not tilt the cylinder while you lower it.

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 seal (107*) with the lips up, and place the seal retainer washer (113) on the piston/valve seat (109). Make sure the lips of the seal face up. See Fig. 3.

17.Place the piston ball (103) in the displacement rod (29).

18.Clean the threads of the piston/valve seat (109), Apply Loctiter to the threads, and thread the assembly from Step 16 onto the displacement rod (29).

19.Clamp the flats of the piston/valve seat (109) in a vise, and torque the displacement rod (29) to the piston valve seat to 45 to 55 ft-lb (61 to 75 N.m).

20.Clamp the air motor base (28) in a vise horizontally by closing the vise jaws on the flange

21.Thread piston assembly tool (A) (included in repair kit 238751) onto the threads of the displacement pump cylinder (110). See Fig. 5.

22.Insert the piston assembly (B) into the displace- ment pump cylinder.

23.Unscrew the piston assembly tool from the dis- placement pump cylinder. Clip the piston assem- bly tool with a diagonal cutter (C), and discard it.

NOTE: Be careful that you do not scratch the rod.

24.Use a strap wrench to screw the displacement pump cylinder (110) to the air motor base (28). See Fig. 3.

25.Before you remount 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.

26.Reconnect the ground wire before regular opera- tion of the pump.

rod

110

Fig. 5

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