Hitachi 308640 manual Air Valve Service, Fluid Needle Cartridge Service

Service

WARNING

INJECTION HAZARD

To reduce the risk of a fluid injection injury, follow the Pressure Relief Proce- dure on page 7 before checking or

servicing any of the system equipment and when- ever you are instructed to relieve pressure.

NOTE:

DFollow the Service Notes in Fig. 8 when reassem- bling the gun. Refer to the parts drawing for your gun model (page 18 or 20) for parts not shown in Fig. 8.

DRepair Kits are available. See page 19 or 21 for the kits for your gun model.

Air Valve Service

1.Relieve the pressure as instructed on page 7.

2.Remove the trigger (3) and valve cap (7). See the parts drawing and Fig. 8.

3.Unscrew the needle nut (23) while holding the flats

(C) of the air valve (26) stem with a long nose pliers.

CAUTION

To avoid leakage, be careful not to scratch the air valve stem.

4.Remove the spring (6) and air valve (26).

5.If there is air leakage at the air valve (26), unscrew the packing nut (24) and carefully remove the u-cup packing (25). Replace packing if worn or damaged. When re-installing, be sure the u-cup faces inward.

6.If leakage occurs internally or the front of the gun leaks air when it's not triggered, clean and inspect the air valve and the spring for wear or damage.

Replace as needed.

7.For best air valve life, lubricate the external air valve stem (C) with light oil after each day's use.

Fluid Needle Cartridge Service

Follow the procedure below to remove the fluid needle cartridge for cleaning or for replacement.

1.Relieve the pressure as instructed on page 7.

2.Remove the tip guard or AA RAC assembly (11), air cap or RAC housing (13), spray tip (14), and air separator (16 ± part no. 238402, 238852, 238883, and 241070 guns only). See Fig. 8.

3.Trigger the gun to back the fluid needle ball off the seat. Remove the diffuser-seat (15).

4.Remove the trigger (3) and trigger extension pieces (19). See the Parts Drawing, page 18.

5.To remove the fluid needle cartridge (10), slide the notch of the packing tool (34) around the small diameter of the trigger guide (A) and pull the cartridge toward the front of the gun.

6.Remove the fluid gasket (18).

7.If the fluid needle cartridge was removed for cleaning, remove the external o-ring (10a) and backup ring (10b). Clean the needle cartridge thoroughly with a compatible solvent and a soft brush. Install a new o-ring (10a) and backup ring (10b).

8.Lubricate the o-ring (10a) and backup ring (10b) of the new or cleaned needle cartridge with light- weight oil.

9.Insert the fluid needle cartridge into the front end of the gun body. Use the packing tool (34) to pull back on the cartridge until it snaps into place; the cartridge must be bottomed out in the gun body insert. If the cartridge is seated properly, the needle cartridge washer (B) will be visibly seated flat through the back end of the gun body insert.

10.Insert a new gasket (18).

11.Install the gun trigger and trigger extension pieces.

12.Lubricate the diffuser-seat (15) thread. Trigger the gun while screwing the diffuser-seat back into the gun. Torque the diffuser-seat to 90 to 100 in-lb (10.2 to 11.2 NSm).

13.Install the gun air separator (part no. 238402, 238852, 238883, and 241070 guns only), spray tip, air cap or RAC housing, and tip guard or AA RAC assembly.

16 308640