Graco Inc. G40 Paint Sprayer User Manual


 
Troubleshooting
18 311001G
Troubleshooting
General Troubleshooting
SKIN INJECTION HAZARD
Follow Pressure Relief Procedure on page 10.
Read warnings, page 4.
Check all possible remedies in the trouble-
shooting charts before disassembling the gun.
Some improper patterns are caused by the
improper balance between air and fluid.
Problem Cause Solution
Fluid leakage from back of fluid
packing area.
Worn packings or needle shaft. Replace needle assembly (2).
Air leakage from gun. Air valve not seating properly. Clean or replace air valve (8).
Fluid leakage from front of gun. Needle ball worn or damaged. Replace needle assembly (2) and seat (5c).
Worn seat assembly. Replace the seat (5c) and gasket (5b, carbide
models only). The gasket must be replaced
whenever the seat assembly is removed.
Do not reverse the direction of the plastic seat
(5c, model 288844 gun only) if it is worn. The
seat must be replaced it if is worn.
Fluid viscosity too low for proper
seal with carbide seat.
Install plastic seat (5c).
Fluid in air passages. Spray tip seal leaking. Tighten retaining ring (6) or replace spray tip
(33).
Leaking around seat housing. Replace the gasket (5b, carbide models only).
The gasket must be replaced whenever the
seat assembly is removed.
Fluid inlet fitting leaking. Replace the fluid tube gasket (22). The gas-
ket must be replaced whenever the fluid tube
connector is removed.
Slow fluid shut-off. Fluid buildup on fluid needle
components.
Remove and clean or replace the fluid needle
assembly (2).
No fluid output when triggered. Spray tip plugged. Clean spray tip. See page 14.
Fluid filter or fluid hose plugged. After tip removal (see above), very slowly
loosen the hose end coupling at the gun and
relieve pressure gradually. Then loosen com-
pletely to clear the obstruction. Clean or
replace filter (12).