Graco 237526, Series B Displacement Pump Service, Intake Valve See Fig, Displacement Pump See Fig

Air Motor and Throat Service

12.Slide the piston rod (29) down through the pack- ing, and lower the piston (27) into the air motor base (28).

13.Clamp the air motor base (28) in a vise horizontally by closing the vice jaws on the flange.

14.Install the u-cup packing (107{) with the lips up, and place the piston washer (113) on the piston/ valve seat (109).

NOTE: Make sure the lips of the u-cup packing (107{) face up. See Fig. 3.

15.Place the piston ball (103) in the piston rod (29).

16.Apply Loctiter to the threads of the piston/valve seat (109), and thread the assembly from Step 14 onto the piston rod (29).

17.Clamp the flats of the piston/valve seat (109) in a vice, and, using a crow’s-foot wrench, torque the piston rod (29) to the piston valve seat to 40 to 60 ft-lb.

18.Clamp the air motor base (28) in a vise horizontally by closing the vice jaws on the flange

19.Use a strap wrench to screw the displacement pump cylinder (110) to the air motor base (28), and torque with a crow’s-foot wrench to 95 to 105 ft-lb.

20.Before remounting the pump, connect an air hose and run the air motor slowly, at about 40 psi (0.28 MPa, 2.8 bar) to see that it operates smoothly.

21.Reconnect the ground wire before regular opera- tion of the pump.

Displacement Pump Service

Disassembly

NOTE: Displacement Pump Repair Kit 237602 includes repair parts for the pump throat and piston. Use all the parts in the kit for the best results. Parts included in the kit are marked with a dagger, for example (7{), in the text and drawings. See the Parts List on page 16.

1.Flush the pump. Follow the Pressure Relief Procedure on page 8, before proceeding.

2.Disconnect the hoses, remove the pump from its mounting, and clamp the air motor base (28) in a vise horizontally by closing the vice jaws on the flange.

1.Follow the Pressure Relief Procedure on page 8.

2.Follow steps 1 through 6 of Disassembly on page 10.

3.Carefully inspect the smooth, inner surface of the cylinder (110) for scoring or irregular surfaces. Such damage causes premature seal wear and leaking. Replace the cylinder as needed.

Reassembly

Do steps 14 through 21 in Air Motor and Throat Service on this page.

Intake Valve See Fig 5.

1. Follow the Pressure Relief Procedure on

page 8.

103

108{

2.	Unscrew the valve housing (111). Remove the
	o-ring (105{), retainer (112), and ball (104).
3.	Inspect the parts for wear or damage. If the ball is

113

110

109

107{ 1

nicked, replace it. Reassemble, using grease on

the male threads.

Displacement Pump See Fig 5.

NOTE: Clean and inspect all parts for wear or damage as you disassemble them. Replace parts as needed. For best results, always replace all the o-rings and packings when you disassem- ble the pump.

112

104

105{	1 Lips face up
111	03847

Fig. 5

{Included in Repair Kit 237602.

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