Troubleshooting

Troubleshooting

 

 

 

 

 

 

 

 

 

 

✖ Fluid ratio will be wrong.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

◆ Purge all air from system before proportioning

 

 

 

 

 

 

 

 

 

 

fluids.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Problem

 

 

Cause

Solution

 

 

 

System stops or will not start.

Air pressure or volume too low.

Increase; check air compressor.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Closed or restricted air line or air

Open or clean.

 

 

 

 

 

 

 

valve.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fluid valves closed.

Open.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Clogged fluid hose.

Replace.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Air motor worn or damaged.

Repair air motor; see 311238.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Displacement pump stuck.

Repair pump; see 311762.

 

 

 

System speeds up or runs erratically.

Fluid containers are empty.◆

Check often; keep filled.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Air in fluid lines.◆

Purge; check connections.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Displacement pump parts worn or

Repair pump; see 311762.

 

 

 

 

 

 

 

damaged.

 

 

 

 

Pump operates, but resin output

Dirty, worn, or damaged resin pump

Clean, repair pump; see 311762.

pressure drops on upstroke.✖

piston valve or piston packings.

 

 

 

 

Pump operates, but resin output

Dirty, worn, or damaged resin pump

Clean, repair pump; see 311762.

pressure drops on downstroke.

intake valve.

 

 

 

 

Pump operates, but resin output

Hardener output restriction.

Clean, unplug hardener side. Open

pressure drops on both strokes.✖

 

 

 

 

manifold restrictor.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Fluid supply low.◆

Refill or change container.

 

 

 

Pump operates, but hardener output

Dirty, worn, or damaged hardener

Clean, repair pump; see 311762.

pressure drops on upstroke.✖

pump piston valve or piston packings.

 

 

 

 

Pump operates, but hardener output

Dirty, worn, or damaged hardener

Clean, repair pump; see 311762.

pressure drops on downstroke.✖

pump intake valve.

 

 

 

 

Pump operates, but hardener output

Resin output restriction.

Clean, unplug resin side.

pressure drops on both strokes.

 

 

 

 

 

Fluid supply low.◆

Refill or change container.

 

 

 

 

 

 

 

 

 

 

Fluid leak in packing nut.

Loose packing nut or worn throat

Tighten; replace; see 311762.

 

 

 

 

 

 

 

packings.

 

 

 

 

Fluid leak under packing nut

Packing cartridge o-ring.

Replace o-ring; see 311762

 

 

 

Relief valve (AM) leaks back to sup-

Relief valve is dirty or damaged.

Replace valve cartridge (302) with kit

ply, opens too soon, or will not close.

 

 

 

 

262520.

 

 

 

No pressure on hardener side; fluid

Overpressure rupture disk blown.

Determine cause of overpressuriza-

leaking from hardener pump outlet

 

 

 

 

tion and correct. Replace rupture disk

rupture disc fitting.

 

 

 

 

assembly (140) and over-pressure

 

 

 

 

 

 

 

 

 

 

 

cartridge (302).

 

 

 

Pressure and flow surges on

Feed pressure too high. Every pound

Reduce feed pressure. See Techni-

upstroke.

of feed pressure adds 2 psi boost

cal Data, page 53.

 

 

 

 

 

 

 

during upstroke.

 

 

 

 

 

 

 

 

 

 

 

 

 

3A0420H

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Image 31
Graco XP70 important safety instructions Troubleshooting, Problem Cause Solution