Hitachi 231580 manual Displacement Pump Repair, Removing the pump See Fig, Repairing the pump

Displacement Pump Repair

WARNING

INJECTION HAZARD

To reduce the risk of serious injury, whenever you are instructed to relieve pressure, follow the Pressure Relief

Procedure on page 9.

NOTE: Packing Repair Kit 235703 is available. Refer- ence numbers of parts included in the kit are marked with an asterisk, i.e., (121*). For the best results, use all the new parts in the kit, even if the old ones still look good.

NOTE: To minimize down time, and for the best sprayer performance, check the motor brushes (see page 19) and clean the transducer (see page 27) whenever you repack the pump. Replace these parts as needed.

Removing the pump (See Fig. 17.)

1.Flush the pump, if possible. Relieve pressure. Stop the pump with the piston rod (107) in its lowest position, if possible. To lower the piston rod manu- ally, rotate the motor fan blades.

2.Loosen the swivel nut on adapter (38) and remove suction hose (32). While pushing in on the collar of elbow (36), pull out and remove drain tube (33).

3.Use a screwdriver to push the retaining spring (18) up and push out the pin (17).

4.Loosen the screws (21). Remove the pump (20).

Repairing the pump

See manual 308190 for pump repair instructions.

Installing the pump (See Fig. 18 and 19.)

1.Mount the pump on the drive housing. Tap it into the alignment pins with a soft hammer. Tighten the screws (21) to 50 ft-lb (68 N.m).

WARNING

MOVING PARTS HAZARD

Be sure the retaining spring (18) is firmly

in the groove all the way around, to pre- vent the pin (17) from working loose due

to vibration. See Fig. 18.

If the pin works loose, it or other parts could break off due to the force of the pump action. These parts could be projected into the air and result in serious injury or property damage, including the pump connecting rod or drive housing.

2.Align the hole in the rod (107) with the connecting rod assembly (15). Use a screwdriver to push the retaining spring (18) up and push in the pin (17).

Push the retaining spring (18) into place around the connecting rod.

3.Replace the o-ring (27) if it is worn or damaged. Reconnect the suction and drain hoses (32,33). Install the front cover (13).

4.Tighten the packing nut (102) just enough to stop leakage, but no tighter. Fill the packing nut/wet-cup 1/3 full with Graco TSL. Push the plug (123) into the wet-cup.

13

				17
	18
	107			120
	20			*122
1	21			*121
			36	*119
			118
	33
	32
	27	1	Torque to
	38		50 ft±lb (68 N.m)
		2	Apply anaerobic
	2		polyacrylate pipe
			sealant
Fig. 17					02832B
				17
	15
	123
				18
1	Torque to
	50 ft±lb (68 N.m)
Fig. 18		21 1		102
					04655

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