Graco Inc 231-353, 390sts, 308-548 Intake valve repair See Fig, Disassembling the pump See Fig

Displacement Pump Repair

Intake valve repair (See Fig. 17)

1.Remove the suction hose. See Step 2, Removing the pump.

2.Unscrew the intake valve (118). Remove the o-ring (119*), ball guide (120), stop pin (122*) and ball (121*) from the valve.

3.Clean and inspect the parts for wear or damage. Replace parts as needed. Use a new o–ring

(119*). If no further service is needed, reassemble the pump.

Disassembling the pump (See Fig. 19.)

1.Remove the intake valve (118). See page

2.Loosen the packing nut (102) and plug (123).

3.Use a plastic mallet to tap the piston rod (107) down, and then pull the rod out through the bottom of the cylinder.

4.Remove the packing nut (102) and throat pack- ings.

5.Loosen the jam nut (117). Remove the cylinder

(115)and the o-ring (116*).

6.Clamp the flats of the piston rod in a smooth jaw vise. Use an open-end wrench to loosen the nut

(110)and then unscrew the piston valve (108).

7.Remove all parts from the piston valve (108).

Reassembling the pump

NOTE: Alternate plastic and leather packings. See Fig.

19.The lips of the throat V-packings face down. The lips of the piston V-packings face up. Incorrect installa- tion damages the packings and causes pump leakage.

NOTE: Soak the leather packings in oil before reas- sembling the pump.

1.Check the outside of the piston rod (107) and the inside of the cylinder (115) for wear. Replace worn parts to ensure a good seal with the new packings.

2.Stack these parts onto the piston valve (108) one at a time: the female gland (114*), alternately three plastic (112*) with two leather packings (113*), and the male gland (111*). See Fig. 19.

1Throat packings

2Piston packings

3 Intake valve

123

102
*103		107
1	105*
*104
	106*	109*
		110
		111
		2
	*113	112*
101
		114*
117		108
*116
		3
115
		118
Fig. 19		01069A