Troubleshooting

 

What to Check

What to Do

 

If check is OK, go to next

When check is not OK,

Problem

check

refer to this column

 

 

 

Pump output is low

Pump rod damage.

Repair pump. See pump manual.

 

 

 

 

Low stall pressure.

Turn pressure knob fully clockwise.

 

 

Make sure pressure control knob is

 

 

properly installed to allow full

 

 

clockwise position. If problem

 

 

persists, replace pressure transducer.

 

 

 

 

Piston packings are worn or

Replace packings. See pump manual.

 

damaged.

 

 

 

 

 

O-ring in pump is worn or damaged.

Replace o-ring. See pump manual.

 

 

 

 

Intake valve ball is packed with

Clean intake valve. See pump

 

material.

manual.

 

 

 

 

Large pressure drop in hose with

Reduce overall length of hose.

 

heavy materials.

 

 

 

 

 

Check extension cord for correct size.

See Extension Cords, page 12.

 

 

 

 

Loose motor brushes and terminals.

Tighten terminal screws. Replace

 

 

brushes if leads are damaged.

 

 

 

 

Worn motor brushes. (Brushes must

Replace brushes.

 

be 1/2 in. [13mm] minimum length.)

 

 

 

 

 

Broken and misaligned motor brush

Replace spring if broken. Realign

 

springs. Rolled portion of spring must

spring with brush.

 

rest squarely on top of brush.

 

 

 

 

 

Motor brushes are binding in brush

Clean brush holders, remove carbon

 

holders.

dust with a small cleaning brush.

 

 

Align brush lead with slot in brush

 

 

holder to assure free vertical brush

 

 

movement.

 

 

 

Motor runs but pump does not stroke

Connecting rod assembly damaged.

Replace connecting rod assembly.

 

See pump manual.

See pump manual.

 

 

 

 

Gears or drive housing damaged.

Inspect drive housing assembly and

 

 

gears for damage and replace if

 

 

necessary.

 

 

 

Excessive paint leakage into throat

Throat packing nut is loose.

Remove throat packing nut spacer.

packing nut

 

Tighten throat packing nut just

 

 

enough to stop leakage.

 

 

 

 

Throat packings are worn or

Replace packings. See pump manual.

 

damaged.

 

 

 

 

 

Displacement rod is worn or

Replace rod. See pump manual.

 

damaged.

 

 

 

 

30

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Image 30
Graco 395/490/495/595 important safety instructions Properly installed to allow full