Graco 231–034 Instructions And Parts List page 19

4 The fluid output is low.
PROBLEM
The fluid output is low.
WHAT TO CHECK
If check is OK, go to next check
1. Check for worn spray tip.
2. Check to see that the pump does not continue
to stroke when the gun trigger is released. Plug
in and turn on the sprayer. Prime the sprayer.
Trigger the gun briefly, then release and lock
the trigger safety. Relieve the pressure, turn off
and unplug the sprayer.
3. Check the electrical supply with a volt meter.
The meter should read 105–125 VAC.
4. Check the extension cord size and length; it
must be at least 12 gauge wire and no longer
than 150 ft.
5. Check the G1 and G2 leads from the bridge
(308) to circuit board (71) for damaged or loose
wires or connectors. Refer to Fig. 17, page 27.
6. Check stall pressure. Refer to Pressure Control
Adjustment on page 30.
7. Check bridge (308) + and – leads and termi-
nals to motor. Inspect wiring insulation and ter-
minals for signs of overheating. See page 27.
8. Check for loose motor brush leads and termi-
nals. See page 25.
9. Check for worn motor brushes which should be
1/2" minimum. See page 25.
10.Check for broken and misaligned motor brush
springs. Rolled portion of spring must rest
squarely on top of brush.
11. Check motor brushes for binding in brush hold-
ers. See page 25.
12.Check circuit board (71) by substituting with a
good circuit board. See page 28.
13.Check motor armature for shorts by using an
armature tester (growler) or perform spin test.
See page 22.
14.Check bridge (308) by substituting with a good
bridge or by performing the bridge test. See
page 23 or 27.
CAUTION: Do not perform this check until ar-
mature is determined to be good. A bad arma-
ture will immediately burn out a good bridge.
WHAT TO DO
When check is not OK refer to this column
1. Follow Pressure Relief Procedure Warn-
ing then replace tip. See your separate gun
or tip manual.
2 Service pump. See pages 37.
3.. Reset building circuit breaker; replace build-
ing fuse. Repair electrical outlet or try an-
other outlet.
4. Replace with a correct, grounded extension
cord.
5. Clean circuit board male terminals. Replace
loose or defective lead terminals. Securely
reconnect lead terminals to board.
6. Perform pressure control adjustment. See
page 30.
7. Be sure male terminal blades are centered
and firmly connected to female terminals.
Replace any loose terminal or damaged wir-
ing. Securely reconnect wires to bridge.
8. Tighten terminal screws. Replace brushes if
leads are damaged. See page 25.
9. Replace brushes. See page 25.
10.Replace spring if broken. Realign spring
with brush. See page 25.
11. Clean the brush holders, remove carbon
dust with a small cleaning brush. Align the
brush lead with the slot in the brush holder
to assure unhindered vertical brush move-
ment.
12.Replace the circuit board. See page 28.
13.Replace the motor. See page 34.
14.Replace the bridge. See page 27.