Troubleshooting. Graco 3A4798F, Pro Xp Waterborne Auto Air Spray Gun

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Troubleshooting. Graco 3A4798F, Pro Xp Waterborne Auto Air Spray Gun | Manualzz



Installing and servicing this equipment requires access to parts which may cause an electric shock or other serious injury if the work is not performed prop erly. Do not install or repair this equipment unless you are trained and qualified.

To reduce the risk of an injury, follow the Pressure

Relief Procedure whenever you are instructed to

relieve the pressure.

Check all possible remedies in the Troubleshooting

Chart before disassembling the gun.

Spray Pattern Troubleshooting

Some spray pattern problems are caused by the improper balance between air and fluid.


Fluttering or spitting spray.

Cause Solution

No fluid.

Refill supply.

Loose, dirty, damaged nozzle/seat. Clean or replace nozzle, page 32.

Improper spray pattern.


Air in fluid supply.

Damaged nozzle or air cap.

Check fluid source. Refill.

Replace, page 32.

Fluid buildup on air cap or nozzle.

Fan air pressure too high.

Fluid too thin.

Fluid pressure too low.

Fan air pressure too low.

Clean. See page 23.


Increase viscosity.



Fluid too thick.

Too much fluid.

Did not apply 50% overlap.

Dirty or damaged air cap.

Reduce viscosity.

Decrease flow.

Overlap strokes 50%.

Clean, page 23 or replace, page 32.

28 3A4798F


Gun Operation Troubleshooting

Problem Cause Solution

Excessive spray fog.

“Orange Peel” finish.

Fluid leaks from the fluid packing area

Air leaks from the air cap

Fluid leakage from the front of the gun

Gun does not spray

Atomizing air pressure too high.

Fluid too thin.

Atomizing air pressure too low.

Poorly mixed or filtered fluid.

Fluid too thick.

Worn packings or rod.

Worn piston stem o-rings.

Worn fluid seat.

Loose fluid nozzle.

Damaged nozzle o-ring.

Low fluid supply.

Damaged air cap.

Dirty or clogged fluid nozzle.

Damaged fluid nozzle.

Piston not actuating.

Actuator arm is out of position.

Decrease air pressure as low as pos sible.

Increase viscosity.

Increase air pressure; use lowest air pressure necessary.

Remix or re-filter fluid.

Reduce viscosity.

Replace; see page 33

Replace; see page 36.

Replace fluid nozzle (4) and/or elec -

trode needle (7); see page 32.

Tighten; see page 32.

Replace; see page 32.

Add fluid if necessary.

Replace; see page 32.

Clean; see page 32.

Replace; see page 32.

Check cylinder air. Check piston

u-cup (34d); see page 36.

Check actuator arm and nuts. See

page 37.

Dirty air cap Misaligned air cap and fluid nozzle. Clean fluid buildup off air cap and

fluid nozzle seat; see page 23.

Damaged nozzle orifice.

Fluid is coming on before the air.

Replace nozzle (4); see page 32.

Check actuator arm and nuts. See

page 37.

Excessive paint wrap back to spray gun

Air leaks from manifold

Poor Grounding

See Grounding, page 16

Incorrect distance from gun to part Should be 8-12 in. (200-300 mm)

Gun not securely tightened to the manifold

Worn or missing o-rings

Tighten manifold screws

Replace o-rings. See page 37

Tighten manifold screws.

Fluid leaks at the quick-disconnect. Gun not securely tightened to the manifold

Fluid seal o-rings are worn or miss ing.

Inspect or replace o-rings.

3A4798F 29


Electrical Troubleshooting


Poor wrap (in general, the external charge gun has less wrap than a direct charge waterborne).


ES On/Off switch is OFF (O).


Turn ON (I).

ES or Hz indicator is not lit

ES indicator light is amber (standard models only)

ES indicator light is red (standard models only)

No voltage or low voltage reading on the Pro Xp Auto Control module

Pro Xp Auto Control Module displays event code (smart models only)

Gun air pressure too low (ES indica tor is amber).


Atomizing air pressure too high.


Incorrect distance from gun to part. Should be 8-12 in. (200-300 mm).

Poorly grounded parts.

Check air pressure to gun; minimum

45 psi (0.32 MPa, 3.2 bar) needed at gun for full voltage.

Faulty gun resistance.

Faulty alternator.

Weak electrostatic field.

Resistance must be 1 megohm or less. Clean workpiece hangers.

See Test Total Gun Resistance


page 25.

Replace alternator.

No power

Install a long charging probe on the gun.

Check power supply, turbine, turbine ribbon cable. See

Power Supply

Removal and Replacement , page

38 and Turbine Removal and

Replacement , page 39.

Turbine speed is too low

Turbine speed is too high

Damaged fiber optic cable or con nection.


Increase air pressure until indicator is green.

Decrease air pressure until indicator is green

Check; replace damaged parts. See

Pro Xp Auto Control Module manual


Turbine air is not turned on.

Turn on.

See manual 332989 for Event Code


30 3A4798F


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