Graco Inc 390sts, 308-548, 231-353 manual 110 108

Displacement Pump Repair

3.Tighten the nut (110) onto the piston valve (108) to 2 in-lb (0.23 N.m). See Fig. 20.

NOTE: Note the alignment of the piston (108) to the nut (110). Maintain this alignment through Step 8.

4.Clean all residue from the piston valve threads. Apply one strip of adhesive, supplied, to the threads.

5.Place the ball (109*) on the piston valve (108). See Fig. 20.

1	Torque to	107
	5 in–lb (0.57 N.m)
	Apply one strip of
2	sealant to these	*109
	threads
		2

110

Fig. 20 108 01070

CAUTION

Step 6, tightening the piston valve into the rod, is critical. Follow the procedure carefully to avoid damaging the packings by overtightening.

6. Hand tighten the valve into the piston rod just until

the nut (110) contacts the rod. See Fig. 21.

Torque nut against rod

1to 30 ft–lb (4o N.m)

Do not allow nut (110)

2 to move relative to piston (108) when tightening piston against rod.

Fig. 21

107

110 1 2

108

01071

7.	Place the flats of the rod (107) in a smooth jaw
	vise.
8.	CAREFULLY tighten the nut (110) against the pis-
	ton rod to 30 ft-lb (40 N.m). See Fig. 21.
	Use two wrenches to maintain the alignment men-
	tioned in NOTE below Step 3.

9.Stack these parts one at a time into the top of the manifold (101): the male gland (106*), alternately three plastic packings (104*) with two leather pack- ings (105*), and then the female gland (103*). See Fig. 23.

10.Install the packing nut (102) and plug (124), but leave loose for now. See Fig. 23.