Graco 308116T important safety instructions Displacement Pump Service, Disassembly, Reassembly

Service

Displacement Pump Service

Disassembly

When disassembling the pump, lay out all removed parts in sequence, to ease reassembly. Refer to Fig 5.

NOTE: Standard Repair Kit 224401 (UHMWPE/PTFE packings) is available. For the best results, use all the new parts in the kit. Parts included in the kit are de- noted with one asterisk, for example (3*).

Conversion Kit 224889 is available to convert the pump to all PTFE packings. See page 19 for details.

Clean all the parts thoroughly when disassembling. Check them carefully for damage or wear, replacing parts as needed.

1.Remove the displacement pump from the air motor as explained on page 12.

2.Unscrew the locking ring (7) from the cylinder (8). See Fig 5. Remove the intake valve housing (15).

3.Remove the o-ring (12), ball stop pin (6), ball guide

(9)and ball (4) from the intake valve housing (15).

4.Loosen the packing nut (2). Push the displacement rod (13) down as far as possible, then pull it out the bottom of the cylinder (8).

5.Secure the flats of the displacement rod (13) in a vise. Using a wrench on the flats of the piston mounting stud (28), screw the piston off the rod. Remove one cotter pin (3) and the ball stop pin (21), taking note which set of holes it is in. Then remove the ball (4).

6.Place the flats of the piston mounting stud (28) in a vise, and unscrew the piston stud (26). Remove the piston packings (20, 23), glands (25, 27), washer (19), and shims (31).

7.Remove the packing nut (2), throat packings (5, 24), and glands (11, 14) from the outlet housing

(1).

8.Inspect all parts for damage. Clean all parts and threads with a compatible solvent before reassem- bling. Inspect the polished surfaces of the dis- placement rod (13) and cylinder (8) for scratches, scoring or other damage, which can cause prema- ture packing wear and leaking. To check, run a finger over the surface or hold the part up to the light at an angle. Be sure the ball seats of the piston (26) and intake valve housing (15) are not chipped or nicked. Replace any worn or damaged parts.

Reassembly

NOTE: On UHMWPE/PTFE packed pumps, the packing order is one UHMWPE packing, two PTFE packings, and one UHMWPE packing. On PTFE packed pumps, all four packings are PTFE.

1.See Fig 5 and the NOTE above. Lubricate the throat packings and install them in the outlet housing (1) one at a time as follows, with the lips of the v-packings facing down: the male gland (11*), the v-packings (24* or 5*), and the female gland (14*). Apply thread lubricant and install the packing nut (2) loosely.

2.If you removed the cylinder (8), apply thread lubricant and reinstall it in the outlet housing (1), making sure to replace the o-ring (10).

3.See Fig 5 and the NOTE above. Install shims (31*) onto the piston stud (26) as required to eliminate end play. Lubricate the piston packings and install them one at a time in the following order, with the lips of the v-packings facing up: the female gland (25*), the v-packings (23* or 20*), the male gland (27*), and the washer (19*).

4.Apply thread sealant and screw the piston stud

(26) onto the piston mounting stud (28). Torque to 50--70 ft-lb (68--95 NSm). Install the piston ball (4*) on the piston seat. Slide the ball stop pin (21*) into the desired set of holes, and secure with the cotter pin (3*).

5.Place the flats of the displacement rod (13) in a vise. Apply sealant and screw the piston assembly onto the displacement rod. Torque to 50--70 ft-lb (68--95 NSm).

6.Insert the displacement rod (13) into the bottom of the cylinder (8), being careful not to scratch the cylinder. Push the rod straight up until it protrudes from the packing nut (2).

7.Install the ball (4*), guide (9), o-ring (12), and ball stop pin (6*) in the intake valve housing (15). Place the intake valve assembly in the locking ring (7). Apply thread sealant to the locking ring and cylin- der (8), and screw the ring onto the cylinder.

8.Reconnect the displacement pump to the air motor as explained on page 12.

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