Graco 231-043 Instructions-Parts List Manual page 20

NO OUTPUT
TYPE OF PROBLEM
Motor runs and pump strokes
Motor runs but pump does not
stroke
EXCESSIVE PRESSURE FLUCTUATIONS
TYPE OF PROBLEM
Spray pattern variations.
WHAT TO CHECK
If check is OK, go to next check
1. Check paint supply.
2. Check for clogged intake strainer.
3. Check for loose suction tube or fittings.
4. Check to see if intake valve ball and piston ball
are seating properly. See page 36.
5. Check for leaking around throat packing nut
which may indicate worn or damaged pack-
ings. See page 36.
1. Check displacement pump connecting rod pin
(43). See page 38.
2. Check connecting rod assembly (68) for dam-
age. See page 32.
3. Be sure crank in drive housing rotates; plug in
sprayer and turn on briefly to check. Turn off
and unplug sprayer. See page 33.
WHAT TO CHECK
If check is OK, go to next check
1. Be sure both G1 and G2 leads from bridge
(308) to circuit board (71) are firmly con-
nected. See Fig 27–1.
2. Check maximum working pressure
ment. Refer to Pressure Control Adjustment
on page 30.
3. Check bourdon tube flag and detector posi-
tion. Turn pressure setting to maximum; flag
should not drag or bind in optical detector slot
of circuit board.
CIRCUIT BOARD
OPTICAL
DETECTOR
FLAG
4. Check circuit board (71) by substituting with a
good board. See page 28.
5. Check LOW OUTPUT section, page 19.
WHAT TO DO
When check is not OK refer to this column
1. Refill and reprime pump.
2. Remove and clean, then reinstall.
3. Tighten; use thread sealant or sealing tape
on threads if necessary.
4. Remove intake valve and clean. Check
balls and seats for nicks; replace if neces-
sary. See page 36. Strain paint before us-
ing to remove particles that could clog the
pump.
5. Replace packings. See pages 36–38. Also
check piston valve seat for hardened paint
or nicks and replace if necessary. Tighten
the packing nut/wet-cup.
1. Replace pin if missing. Be sure retainer
spring (42) is fully in groove all around con-
necting rod. See page 38.
2. Replace connecting rod assembly . See
page 32.
3. Check drive housing assembly for damage
and replace if necessary. See page 33.
WHAT TO DO
When check is not OK refer to this column
1. Reconnect securely. See page 27.
adjust- 2. Perform pressure control adjustment. See
page 30.
3. Carefully bend flag into alignment with de-
tector slot to see if that corrects problem. If
not, replace bare pressure control assem-
bly (301). Perform pressure control adjust-
ment after reassembly.
4. Replace circuit board. See page 28.