Graco Standard Series Operation, Parts page 31

PROBLEM
Displacement pump operates,
but output is low on upstroke
Displacement pump operates
but output is low on downstroke
and/or on both strokes
Paint leaks and runs over side of
wet-cup
Excessive leakage around
hydraulic motor piston rod wiper
Fluid delivery is low
Sprayer overheats
Spitting from gun
Excessive hydraulic pump noise
*Check hydraulic fluid level often. Do no allow it to become too low. Use only Graco approved hydraulic fluid, page 18.
334606B
CAUSE
Piston ball check not seating
properly
Piston packings worn or
damaged
Piston packings worn or
damaged
Intake valve ball check not
seating properly
Displacement pump air leak
Loose wet-cup
Throat packings worn or
damaged
Piston rod seal worn or
damaged
Pressure setting too low
Displacement pump outlet filter
(if used) is dirty or clogged
Hydraulic motor is worn or
damaged
Large pressure drop in fluid
hose
Paint build up on hydraulic
components
Oil level is low
Inlet to hydraulic pump
pulley/cooling fan is obstructed
Inlet to 3 phase electric motor
cooling fan is obstructed.
Air in fluid pump or hose
Fluid supply is low or empty
Low hydraulic fluid level
Air in hydraulic lines
Troubleshooting
SOLUTION
Service piston ball check. See
manual 334654
Replace packings. See manual
334654
Tighten packing nut or replace
packings. See manual 334654
Service intake valve ball check.
See manual 334654
Tighten wet-cup enough to stop
leakage.
Replace packings. See manual
334654
Replace these parts. See
Repair manual.
Increase pressure, see
Operation manual.
Clean filter.
Bring sprayer to Graco
distributor for repair.
Use larger diameter or shorter
hose.
Clean hydraulic components.
Fill with oil. See Operation
manual.
Remove obstructions.
Remove obstructions.
Check for loose connections on
siphon assembly, tighten, then
reprime pump.
Refill supply container.
Turn sprayer OFF. Add fluid*.
Bleed lines. See Repair manual.
31