Graco 190ES 309063F Repair Manual page 11

LOW OR FLUCTUATING OUTPUT
TYPE OF PROBLEM
Motor runs and pump strokes
Motor runs but pump does not
stroke
Motor is hot and runs intermit-
tently
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 26.
5. Leaking around throat packing nut which may
indicate worn or damaged packings. See
page 26.
6. Pump rod damage.
7. Capacitor failure. Visually inspect capacitor
near terminals. Ensure that orange safety re-
lief plug is intact.
1. Displacement pump pin (9a) (damaged or
missing), page 26.
2. Connecting rod assembly (9) for damage,
page 24.
3. Gears or drive housing, page 24.
1. Be sure ambient temperature where sprayer
is located is not more than 115 _F (46 _C) and
sprayer is not located in direct sun.
2. Motor has burned windings indicated by re-
moving positive (red) brush and seeing
burned adjacent commutator bars.
3. Tightness of pump packing nut. Overtighten-
ing tightens packings on rod, restricts pump
action and damages packings.
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 26. Strain paint before using to
remove particles that could clog pump.
5. Replace packings, page 26. Also check
piston valve seat for hardened paint or
nicks and replace if necessary. Tighten
packing nut/wet-cup.
6. Repair pump, page 26.
7. Replace capacitor.
1. Replace pump pin if missing. Be sure re-
tainer spring (9b) is fully in groove all
around connecting rod, page 26.
2. Replace connecting rod assembly,
page 24.
3. Inspect drive housing assembly and gears
for damage and replace if necessary,
page 24.
1. Move sprayer to shaded, cooler area if pos-
sible.
2. Replace motor. See page 25, Motor Re-
placement.
3. Loosen packing nut. Check for leaking
around throat. Replace pump packings if
necessary. See pump manual 309060.
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309063