Repair

Lower Reassembly

3.Install o-ring retainer (20). Lubricate o-ring (22*) and slide it on over the threads of piston shaft. Apply

1.Lubricate the new piston seal (25*) and install it on the piston.

2.Install the piston plate (24) with the beveled edge facing away from the piston seal. See FIG. 7.

20

19

 

21

high strength (red) Loctite® 263 or 2760 to entire length of the piston rod (19) threads. Sealant must be allowed to cure for a minimum of 12 hours before use. Screw the piston nut (21) snugly against the o-ring retainer (20). Apply lubricant to the bottom face of the piston nut (21). Assemble o-ring (23*) and install in the groove on the piston nut. Screw rod (19) into piston (26) until snug. Tighten piston nut (21) to 270-285 N•m. (200-210 ft-lb).

4 3

8

23*

4. Remove the piston assembly from the vise, but do not lay it down on its side; doing so may dam-

24age the seal.

*22

1

25*

 

 

1

26

TI0219

1Apply lubricant.

3Torque to 200-210 ft-lb (270-285 N•m).

4Apply lubricant to face of piston nut.

8Apply high strength (red) Loctite® 263 or 2760 to entire length of threads. Sealant must be allowed to cure for a minimum of 12 hours before use.

FIG. 7. Piston Assembly

5.Carefully and evenly guide the seal and the piston into the cylinder. The piston seal and piston may need to be tipped at an angle and the exposed, leading lip of the seal tapped into the cylinder with a plastic mallet. After the seal lip has entered the cyl- inder use an arbor press or tap the bottom of the piston assembly lightly with a plastic mallet to slide the piston assembly into the cylinder. Before press- ing, ensure the piston seal lips are started into the cylinder. See FIG. 9.

6.Clean the remaining pump parts in a compatible sol- vent.

26

25

Tighten the tool on the widest part of the shaft (19). Grip the tool with a wrench and unscrew the shaft.

19

4

19

TI0221

 

01413

 

1 Do not damage edges of seal.

 

 

 

FIG. 8. Tool Kit 220385

 

 

FIG. 9. Install Piston in Cylinder

 

 

 

 

3A0540L

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Graco 4000cc, 3000cc important safety instructions Lower Reassembly, Age the seal