Hitachi 206699, SERIES J Air Motor Service, Before you start, Air Motor & Throat Disassembly

Air Motor Service

Before you start:

DHave all necessary parts on hand. Always replace the glands and bearing when replacing the pack- ings. Use all the parts in the repair kits for the best results. See page 18 to order the kits.

DAir Motor Repair Kit 206728. Parts included in this kit are marked with a dagger, (for example, 36†), in the text and drawings.

DDisplacement Pump Repair Kit 206925. Parts included in this kit are marked with one asterisk, (i.e., 6*), in the text and drawings.

DTwo accessory tools should be ordered. Use Padded Pliers, 207579, to grip the trip rod without damaging its surface. Use Gauge, 171818, to ensure the proper clearance between the poppets and seat of the transfer valve.

Air Motor & Throat Disassembly

WARNING

To reduce the risk of serious injury whenever you are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 8.

1.Flush the pump.

2.Relieve the pressure before proceeding.

3.Disconnect the hoses, remove the pump from its mounting, and clamp the air motor base (55) in a vise.

4.Use a strap wrench on the riser tube (12) to screw it out of the air motor base (55).

5.Pull the connecting rod (10) down as far as it will go.

6.Use a hammer and punch to remove the roll pin

(4). Unscrew the connecting rod (10). See Fig. 6.

CAUTION

Do not damage the plated surface of the trip rod (54). Damaging the surface of the trip rod can result in erratic air motor operation. Use the special Padded Pliers, Part Number 207579, to grasp the rod.

7.Manually push up on the piston rod (41) to move the piston assembly (59) up as far as it will go. Unscrew the cap nut (47). Pull the nut up. Grip the trip rod (54) with padded pliers, and screw the nut off the rod. See Fig. 6.

CAUTION

To avoid damaging the cylinder wall, lift the

cylinder (51) straight up off the piston (59). Never tilt the cylinder as it is being removed.

8.Remove the six screws (25). See Fig. 6. Pull the cylinder (51) straight up off the piston (59).

9.Use a screwdriver to push down on the trip rod yoke (28), and snap the toggles down. See Fig. 7.

47

27

51 54

	38
	39†
	42
25	44*
59	1
55
43

41	4*
10	12
1	See detail below.

50*

48* 2 49*

2Lips of v-packings must face down.

04210B

Fig. 6

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