Graco 309868D Displacement Pump Service, Flush the pump and relieve the pressure

Displacement Pump Service

Displacement Pump Service

Be sure you have all necessary parts on hand. Pump Repair Kit 246918 includes repair parts for the pump and air motor. Use all of the parts in the kit for the best results. Parts included in the kit are marked with one asterisk, for example (13*), in the text and drawings. See Parts, page 14.

1.Flush the pump and relieve the pressure.

To reduce the risk of serious injury whenever you are instructed to relieve pressure, always follow the Pressure Relief Procedure on page 6.

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

3.Unscrew the intake valve housing (106) from the fluid cylinder (105). Disassemble the intake valve (see Parts, page 14). Clean and inspect the parts for wear or damage, and replace parts as needed. Be sure to check the o-ring (104*). Unless further intake valve service is needed, reassemble and reinstall, using liquid sealant on the male threads.

4.Use a strap wrench on the fluid cylinder (105) to screw it out of the air motor base (28). Carefully inspect the smooth inner surface of the cylinder for scoring or irregular surfaces. Such damage causes premature packing wear and leaking, so replace the part if it is damaged.

5.Using wrenches on the flats of the displacement rod (29) and on the flats of the fluid piston (107), unscrew the fluid piston from the displacement rod.

6.Take the piston ball (100) out of the displacement rod (29), and take the packing o-ring (102*) off of the fluid piston (107).

7.Clean and inspect the parts. Use all the repair kit parts during reassembly, and replace other parts as necessary.

8.Place the piston ball (100) in the displacement rod (29).

9.Install the new packing o-ring (102*) on the fluid piston (107).

10.Clamp the flats of the fluid piston (107) in a vice and torque the displacement rod (29) to the piston to 40 to 60 ft-lb (54 to 81 N•m).

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

12.Use a strap wrench to screw the fluid cylinder (105) to the air motor base (28), and torque to

40 to 60 ft-lb (54 to 81 N•m).

13.If you disconnected the ground wire, reconnect it before you resume regular pump operation.

12 309868D