Troubleshooting Guide - Graco Series B Instructions-Parts List Manual

WARNING
Pressure Relief Procedure
To reduce the risk of serious bodily injury, splashing
in the eyes or on the skin, or injury from moving
parts, always follow this procedure whenever you
shut off the pump, when checking or servicing any
part of the system, when installing, cleaning or
changing spray nozzles, and whenever you stop
spraying.
1. Shut off the air to the pump.
2. Close the bleed–type master air valve (required
in your system).
3. Close the pump air valve.
4. Close the pump restrictor valve.
5. Shut off the air to the agitator (if used).
6. Hold a metal part of the spray gun firmly to the
side of a grounded metal pail, and trigger the
spray gun to relieve pressure.
7. Open the drain valve, having a container ready
to catch the drainage.
8. Leave the drain valve open until you are ready to
spray again.
PROBLEM
Pump operates but:
–output low on
both strokes
Pump operates but:
–output low on
downstroke
Pump operates but:
–output low on
upstroke
Erratic or accelerated
pump speed
Pump fails to operate
Leakage around
restrictor valve
8 306560

TROUBLESHOOTING GUIDE

CAUSE
Restricted line or inadequate air
supply
Insufficient air pressure, closed or
clogged air valves, etc.
Exhausted fluid supply.
Obstructed fluid hose or spray gun
Loose packing nut or worn packings
Held open or worn intake valve
Held open or worn piston valve or pack-
ings
Exhausted fluid supply.
Held open or worn intake valve
Held open or worn piston valve or pack-
ings
Restricted line or inadequate air
supply
Incorrect restrictor valve setting
Insufficient air pressure, closed or
clogged air valves, etc.
Exhausted fluid supply.
Damaged air motor.
Worn or clogged fluid intake valve, pis-
ton or packings.
NOTE: Check everything in the guide below before dis-
assembling the pump.
NOTE: *To clear the pump, follow the Pressure Relief
Procedure Warning, to the left. Disconnect the
fluid line. If the pump starts when the air is turn
on, then the fluid hose or spray gun is obstructed.
SOLUTION
Clear lines; increase air supply.
Open, clear.
Refill and reprime, or flush.
Clear.*
Tighten, replace.
Clear, service.
Clear, service.
Refill and reprime, or flush.
Clear, service.
Clear, service.
Clear lines; increase air supply.
Adjust. See OPERATION.
Open, clear.
Refill and reprime, or flush.
Service. See manual 307–851.
Clear, service.