Graco 17C407 Operation, Parts page 26

Troubleshooting
Problem
Pump output is low
Motor runs but pump does not stroke
Excessive paint leakage into throat
packing nut
26
What to Check
If check is OK, go to next
check
Pump rod damage.
Low stall pressure.
Piston packings are worn or
damaged.
O-ring in pump is worn or damaged.
Intake valve ball is packed with
material.
Large pressure drop in hose with
heavy materials.
Check extension cord for correct size. See Extension Cords, page 8.
Loose motor brushes and terminals.
Worn motor brushes. (Brushes must
be 1/2 in. [13mm] minimum length).
Broken and misaligned motor brush
springs. Rolled portion of spring must
rest squarely on top of brush.
Motor brushes are binding in brush
holders.
Connecting rod assembly damaged.
See pump manual.
Gears or drive housing damaged.
Throat packing nut is loose.
Throat packings are worn or
damaged.
Displacement rod is worn or
damaged.
What to Do
When check is not OK,
refer to this column
Repair pump. See pump manual.
Turn pressure knob fully clockwise.
Make sure pressure control knob is
properly installed to allow full
clockwise position. If problem
persists, replace pressure transducer.
Replace packings. See pump manual.
Replace o-ring. See pump manual.
Clean intake valve. See pump
manual.
Reduce overall length of hose.
Tighten terminal screws. Replace
brushes if leads are damaged.
Replace brushes.
Replace spring if broken. Realign
spring with brush.
Clean brush holders, remove carbon
dust with a small cleaning brush.
Align brush lead with slot in brush
holder to assure free vertical brush
movement.
Replace connecting rod assembly.
See pump manual.
Inspect drive housing assembly and
gears for damage and replace if
necessary.
Remove throat packing nut spacer.
Tighten throat packing nut just
enough to stop leakage.
Replace packings. See pump manual.
Replace rod. See pump manual.
334603E