18
NO OUTPUT
TYPE OF PROBLEM
WHAT TO CHECK
If check is OK, go to next check
WHAT TO DO
When check is not OK refer to this column
Motor runs and pump strokes
1. Check paint supply.
1. Refill and reprime pump.
2. Check for clogged intake strainer.
2. Remove and clean, then reinstall.
3. Check for loose suction tube or fittings.
3. Tighten; use thread sealant or sealing tape
on threads if necessary.
4. Check to see if intake valve ball and piston
ball are seating properly. See page 34.
4. Remove intake valve and clean. Check
balls and seats for nicks; replace if neces-
sary. See page 34. Strain paint before us-
ing to remove particles that could clog the
pump.
5. Check for leaking around throat packing nut
which may indicate worn or damaged pack-
ings. See page 34.
5. Replace packings. See pages 39–41. Also
check piston valve seat for hardened paint
or nicks and replace if necessary. Tighten
the packing nut/wet-cup.
Motor runs but pump does not
stroke
1. Check displacement pump connecting rod
pin (43). See page 36.
1. Replace pin if missing. Be sure retainer
spring (65) is fully in groove all around con-
necting rod. See page 39.6
2. Check connecting rod assembly (68) for dam-
age. See page 30.
2. Replace connecting rod assembly . See
page 30.
3. Be sure crank in drive housing rotates; plug in
sprayer and turn on briefly to check. Turn off
and unplug sprayer. See page 31.
3. Check drive housing assembly for damage
and replace if necessary. See page 31.
EXCESSIVE PRESSURE FLUCTUATIONS
TYPE OF PROBLEM
WHAT TO CHECK
If check is OK, go to next check
WHAT TO DO
When check is not OK refer to this column
Spray pattern variations.
1. Be sure both G1 and G2 leads from bridge
(308) to circuit board (79) are firmly con-
nected. See page 26.
1. Reconnect securely. See page 26.
2. Check maximum working pressure adjust-
ment. Refer to Pressure Control Adjustment
on page 28.
2. Perform pressure control adjustment. See
page 30. 28
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
3. Carefully bend flag into alignment with de-
tector slot to see if that corrects problem.
If not, replace bare pressure control as-
sembly (301). Perform pressure control
adjustment after reassembly.
4. Check circuit board (79) by substituting with
a good board. See page 26.
4. Replace circuit board. See page 26.
5. Check LOW OUTPUT section, page 16.
