Troubleshooting Guide; Repair - Graco GM 3500 Instructions-Parts List Manual

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 off the sprayer, when checking, adjusting or
cleaning the system, and when changing spray tips.
1. Engage the gun safety latch.
2. Turn 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.
1,5
Check everything in the chart before disassembling the sprayer. (Continued on page 14)
PROBLEM
Engine/sprayer won't start
Engine won't "pull over"
Engine operates, but displacement
pump doesn't

TROUBLESHOOTING GUIDE

WARNING
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CAUSE
Engine switch not on
Out of gas
Engine oil level low
Spark plug cable disconnected or
spark plug damaged
Water frozen in pressure control
Oil seepage into combustion
chamber
Pressure control switch turned OFF
Pressure setting too low
Displacement pump outlet filter dirty
Tip or tip filter clogged
Displacement pump rod seized by
dry paint
Connecting rod worn or damaged
Drive housing worn or damaged
Electrical power not energizing field
Clutch worn or damaged
Pinion assembly worn or damaged
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.
SOLUTION
Turn on.
Replenish
Try starting engine. If light on rear of engine
glows, replenish oil.
Connect cable on top of engine or replace spark
plug.
Return pressure control to authorized Graco
dealer for repair.
Remove spark plug. Pull starter rope 3 or 4 times.
Clean and replace plug. Try to start. Keep spray-
er upright to avoid oil seepage.
Turn on.
Increase pressure.
Clean filter.
Clean tip or tip filter.
Service pump. See page 18.
Replace. See page 20.
Replace. See page 21.
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.
Service. See page 24.
Service. See page 22.
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