Graco NOVA Repair Manual page 8

LOW OR FLUCTUATING OUTPUT
TYPE OF PROBLEM
Motor runs and pump strokes
Motor runs but pump does not
stroke
8
824191
Troubleshooting
WHAT TO CHECK
If check is OK, go to next check
1. Paint supply.
2. Intake strainer clogged.
3. Suction tube or fittings loose.
4. To see if intake valve ball and piston ball are
seating properly. See page 17.
5. Leaking around throat packing nut which may
indicate worn or damaged packings. See
page 17.
6. Pump rod damage.
1. Displacement pump pin (9a) (damaged or
missing), page 17.
2. Connecting rod assembly (9) for damage,
page 15.
3. Gears or drive housing, page 15.
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, page 17. Strain paint before using to
remove particles that could clog pump.
5. Replace packings, page 17. Also check
piston valve seat for hardened paint or
nicks and replace if necessary. Tighten
packing nut/wet-cup.
6. Repair pump, page 17.
1. Replace pump pin if missing. Be sure re-
tainer spring (9b) is fully in groove all
around connecting rod, page 17.
2. Replace connecting rod assembly,
page 15.
3. Inspect drive housing assembly and gears
for damage and replace if necessary,
page 15.