Service

Prepare the Gun for Service

WARNING

ELECTRIC SHOCK HAZARD Installing and servicing this equipment requires access to parts that may cause electric shock or other serious injury if

the work is not performed properly. Do not install or service this equipment unless you are trained and qualified.

WARNING

PRESSURIZED EQUIPMENT HAZARD

To reduce the risk of injury, follow the Pressure Relief Procedure on page 11 before checking or servicing any part of the system and whenever you are instructed to relieve the pressure.

NOTE:

DCheck all possible remedies in Troubleshooting before disassembling the gun.

DIf the plastic parts of the gun must be held securely, always clamp them in padded vice jaws to prevent damage to the parts.

DLightly lubricate o-rings and seals with petroleum jelly. Do not over-lubricate.

DOnly use genuine Graco parts. Do not mix or use parts from other PRO Gun models. See page 35.

1.Flush the gun as instructed in Flush the Spray Gun, page 15.

2.Relieve the pressure.

3.Disconnect the air and fluid lines from the gun.

4.Remove the spray gun from the worksite for service or repair. Service or repair area must be clean.

Air Cap/Nozzle/Resistor Stud Replacement

CAUTION

Hold the front end of the gun up and trigger the gun while removing the nozzle and resistor stud to help drain the gun and prevent any paint or solvent left in the gun from entering the air passages.

1.Prepare the gun for service as instructed at left.

2.Remove the air cap assembly. Point front end of the gun up and squeeze the trigger while removing the fluid nozzle/resistor stud (21, 22) assembly with the multi-tool (62). See Fig.11, page 23.

NOTE: If the resistor stud remains in the gun when the fluid nozzle is removed, start the nozzle thread onto the stud and pull the stud out.

3.Unscrew and remove the resistor stud (22) with the multi-tool (62). See Fig. 12.

WARNING

FIRE, EXPLOSION, AND

ELECTRIC SHOCK HAZARD

The resistor stud contact ring (D) is a conductive contact ring, not a sealing o-ring. See Fig. 11. To reduce the risk of sparking or electric shock, do not remove the resistor stud contact ring (D) except to replace it and never operate the gun without the contact ring in place. Do not replace the contact ring with anything but a genuine Graco part.

To install the resistor stud:

4.Lightly lubricate the o-ring (25) with petroleum jelly and install it on the resistor stud (22).

5.Using the multi-tool (62), install the resistor stud (22) in the fluid nozzle (21). Tighten to 10 in-lb (1.12 NSm).

NOTE: Make sure the electrode needle (20) is tight- ened properly, as shown in Fig. 13.

Continued on the next page.

22 308131

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Image 22
Graco Inc 224200, 308131, 224400, PRO 4500sc manual Prepare the Gun for Service, Air Cap/Nozzle/Resistor Stud Replacement