Graco Inc 308-548, 390sts, 231-353 manual 107 116

Displacement Pump Repair

11.Place a new o-ring (116*) firmly in the cylinder groove. See Fig. 22.

12.Coat the piston rod and packings with oil. Carefully slide the assembly into the top of the cylinder (115). See Fig. 22.

13.Put the manifold upside down in a vise. Fully thread the jam nut (117) onto the cylinder (115). Guide the rod/cylinder assembly down through the manifold (101). Screw the cylinder (115) into the manifold. See Fig. 22.

102

101

15.Torque the cylinder jam nut (117) to 73 ft-lb (98 N.m). See Fig. 22.

16.Install the pump. See page 22.

1	Leather packings	4	Lips of V–packings
			must face up
	Poly packings
2			Torque to 53 ft–lb
		5
3	Lips of V–packings		(71 N.m)
	must face down

107

123

102

Torque jam nut (117)

1to 73 ft–lb (98 N.m)

Torque cylinder (115)

2into manifold (101) to 53 ft–lb (71 N.m)

Torque intake valve (116)

3into cylinder (115) to 53 ft–lb (71 N.m)

4Piston assembly

4

Fig. 22

107

116*

1171

1152

1183

01072A

*103			104*
*105			2	3
			106*
1	3
*116			101
			109*
	110		117
	111		112*
	*113		2	4
	1	4	114*
	115		108*
	120		122*
	*119		121*

14.Place the ball guide (120), stop pin (122) and ball (121*) in the cylinder (115). Screw the intake valve into the cylinder and torque to 53 ft-lb

(71 N.m). This will also properly torque the cylinder into the manifold. See Fig. 23.

5	118
Fig. 23		01073