Graco 795 Paint Sprayer User Manual


 
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Troubleshooting
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. Paint supply. 1. Refill and reprime pump.
2. For clogged intake strainer. 2. Remove and clean, then reinstall.
3. For loose suction tube or fittings. 3. Tighten; use thread sealant or sealing tape
on threads if necessary.
4. To see if intake valve ball and piston ball are
seating properly. See page 17.
4. Remove intake valve and clean. Check
balls and seats for nicks; replace if neces-
sary. See page 17. Strain paint before us-
ing to remove particles that could clog
pump.
5. For leaking around throat packing nut which
may indicate worn or damaged packings. See
page 17.
5. Replace packings. See page 17. Also
check piston valve seat for hardened paint
or nicks and replace if necessary. Tighten
packing nut/wet-cup.
Motor runs but pump does not
stroke
1. Displacement pump connecting rod pin (66).
See page 17.
1. Replace pin if missing. Be sure retainer
spring (68) is fully in groove all around con-
necting rod. See page 17.
2. Connecting rod assembly (63) for damage.
See page 14.
2. Replace connecting rod assembly. See
page 14.
3. Be sure crank in drive housing rotates; plug in
sprayer and turn on briefly to check. Turn off
and unplug sprayer. See page 15.
3. Inspect drive housing assembly for dam-
age and replace if necessary. See page 15.
EXCESSIVE PRESSURE FLUCTUATIONS
TYPE OF PROBLEM
WHAT TO CHECK
If is OK, go to next check
WHAT TO DO
When is not OK refer to this column
Spray pattern variations. 1. Be sure leads to motor control board are firmly
connected. Be sure all male terminal blades
are centered and firmly connected to female
terminals. See Fig. 17.
1. Reconnect securely. See Fig. 17.
2. Maximum working pressure. 2. Replace pressure control board (104).
See page 12.
3. Motor control board (104) by performing motor
control board diagnostics on page 12. If diag-
nostics indicate, substitute with a good board.
CAUTION: Do not perform this check until
motor armature is determined to be good. A
bad motor armature can burn out a good
board.
3. Replace with a new pressure control board
(104). See page 12.
4. Check LOW OUTPUT section, page 6.