Repair

Repair

Follow Pressure Relief Procedure, page 8.

See Parts, page 16, for callout references.

Disassembly

1.Unscrew retaining ring (14) to remove air cap (13b). Check o-rings (13a and 13c) and replace if necessary.

2.Trigger gun while unscrewing nozzle (11) to prevent needle damage.

3.Check o-ring (19) and replace if necessary.

4.Remove fluid control valve (8), spring (26), needle (9), and nut (7). Inspect. Replace tip (9c), needle (9), and u-cup seal (20) as necessary. If replacing needle tip, use low strength thread adhesive on needle tip threads.

5.Remove spring (28) and push the air valve assembly (6) out the back of the gun. Inspect. Replace air valve assembly (6) and u-cup seal (20) as necessary. Use tool (33) to install u-cup seal.

6.Remove trigger nut (22), trigger pin (21), wave washer (18), and trigger (10).

7.Unscrew needle packing nut (17) and remove u-cup packing (16) and spreader (15).

8.Remove air control valve assembly (5). Inspect and replace as necessary.

9.Remove air inlet valve assembly (27). Inspect and replace as necessary.

Fluid Inlet Fitting Replacement

PRESSURIZED EQUIPMENT HAZARD

Fluid inlet gasket (3) must be replaced if fluid inlet fitting (4) is removed from spray gun.

Failure to replace gasket (3) may result in air leakage into the fluid section causing a non-vented gravity cup to become pressurized.

1.Remove fluid inlet fitting (4).

2.Remove fluid inlet gasket (3) from gun body and discard.

3.Apply thread sealant to replacement fluid inlet fitting (4) threads.

4.Snap the fluid inlet gasket (3) securely onto the fluid inlet fitting (4).

5.Screw in fluid inlet fitting (4) and torque to 155-165 in.-lb (17.5-18.6 N•m).

6.Replace washer (28) as required.

14

312579K

Page 14
Image 14
Graco 312579K Repair, Disassembly, Fluid Inlet Fitting Replacement, Follow Pressure Relief Procedure