Troubleshooting

PROBLEM

CAUSE

SOLUTION

 

 

 

 

 

 

Fluid pressures not balanced

Fluid viscosities not equal

Adjust A and B temperature settings

between A and B side

 

to balance viscosity. Sometimes nor-

 

 

mal if pressure offset is below 200 psi

 

 

(14 bar)

 

 

 

 

 

Preheat material in drums by recircu-

 

 

lating; see Operation manual

 

 

 

 

Inlet Y-strainer screen plugged on low

Clean inlet filter screen

 

pressure side

 

 

 

 

 

Gun port or filter plugged on high

Clean or replace; see gun manual

 

pressure side

 

 

 

 

 

Pump inlet ball not seating or sticking

Clean seating; see pump manual

 

 

 

 

Drum fluid outlet supply hose too

Use 3/4 in. (1.9 cm) ID hose with

 

small

short length

 

 

 

 

Low side feed pump not working

Turn on or repair feed pump

 

 

 

 

Pressure Relief/Spray valve leaking

 

 

back to supply

 

 

 

 

Pump does not reverse direction

Obstruction of air motor or pumps

Check and clear obstruction

 

 

 

Unequal fluid pressure between

Feed pumps boost pressure on up

Reduce feed pump pressures

UP/DOWN stroke

stroke.

 

 

 

 

Air motor doesn’t move with air pres-

Damaged air valve

Replace or service air valve. See Air

sure applied

 

Motor manual.

 

 

 

 

Damaged pilot valve

Replace valve. See Air Motor man-

 

 

ual.

 

Park valve left open or leaking

 

 

 

 

 

Pump movement speed is erratic

Worn air motor seals

Replace seals. See Air Motor man-

 

 

ual.

 

 

 

 

Worn pump seals

Replace seals; see Pump manual.

 

 

 

Electronics

Problem

Cause

Solution

 

 

 

 

 

 

 

 

 

 

 

Plug in power cord.

 

 

 

 

 

No power.

Turn disconnect ON

.

Display does not illuminate.

 

 

 

 

 

 

 

Low voltage.

Ensure input voltage is within specifi-

 

 

cations, page 36.

 

 

 

 

 

Loose wire.

Check connections, page 36.

 

 

 

 

Display disconnected.

Check cable connections, page 36.

 

 

 

 

Display disconnected.

Check cable connections, page 36.

 

 

 

 

Display cable damaged or corroded.

Clean connections; replace cable if is

 

 

damaged.

 

Temperature display does not

 

 

 

illuminate.

 

 

 

 

 

 

 

3A1570A

17

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Graco A-25 important safety instructions Electronics, Problem Cause Solution