Graco GM 3500 - TROUBLESHOOTING GUIDE; Common Problems and Solutions

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TROUBLESHOOTING GUIDE
Pressure Relief Procedure
To reduce the risk of serious bodily injury , including fluid
injection, splashing in the eyes or on the skin, or injury
from moving parts, always follow this procedure when
you shut of f the sprayer , when checking, adjusting or
cleaning the system, and when changing spray tips.
1. Engage the gun safety latch.
2. T urn the engine stop lever to OFF .
3.
Flip the pressure control switch to OFF .
4. Disengage
the gun safety latch. Hold a metal part
of the gun firmly to the side of a grounded metal
pail,
and trigger the gun.
5. Engage the gun safety latch.
6. Open the fluid pressure drain valve and leave it
open
until you start the sprayer again.
7. Disconnect the spark plug.
If you suspect the hose or spray tip is completely
clogged
or that pressure is not fully relieved after fol -
lowing
the steps above, wrap a rag around the tip re -
taining
nut or hose end coupling and VER Y SLOWL Y
loosen the part to relieve pressure gradually. Now
clear
the tip or hose.
WARNING
0139
1,5 2 3 4 6
Check everything in the chart before disassembling the sprayer . (Continued on page 14)
PROBLEM CAUSE SOLUTION
Engine/sprayer won’t start Engine switch not on T urn on.
Out of gas Replenish
Engine oil level low Try starting engine. If light on rear of engine
glows,
replenish oil.
Spark plug cable disconnected or
spark plug damaged
Connect cable on top of engine or replace spark
plug.
Water frozen in pressure control Return pressure control to authorized Graco
dealer
for repair .
Engine won’t “pull over” Oil seepage into combustion
chamber
Remove spark plug. Pull starter rope 3 or 4 times.
Clean and replace plug. T ry to start. Keep spray -
er upright to avoid oil seepage.
Engine operates, but displacement
pump doesn’t
Pressure control switch turned OFF T urn on.
Pressure setting too low Increase pressure.
Displacement pump outlet filter dirty Clean filter .
T ip or tip filter clogged Clean tip or tip filter .
Displacement pump rod seized by
dry paint
Service pump. See page 18.
Connecting rod worn or damaged Replace. See page 20.
Drive housing worn or damaged Replace. See page 21.
Electrical power not energizing field Check wiring connections. See page 16.
With pressure control switch ON and pressure
turned to MAXIMUM, use a test light to check
continuity across black and white wires from
pressure
control.
Have pressure control checked by authorized
Graco
dealer .
Clutch worn or damaged Service. See page 24.
Pinion assembly worn or damaged Service. See page 22.