Graco ultra max ii Repair Manual page 12

TYPE OF PROBLEM
Pump output is low
Motor runs but pump does
not stroke
Excessive paint leakage into
throat packing nut
Fluid is spitting from gun
Pump is difficult to prime
No display, sprayer operates 1. Display is damaged or has bad
12
WHAT TO CHECK
If check is OK, go to next check
14. O-ring in pump is worn or dam-
aged
15. Intake valve ball is packed with
material
16. Pressure setting is too low
17. Large pressure drop in hose with
heavy materials
1. Displacement pump pin (32)
damaged or missing; see pump
manual 310643 or 310894.
2. Connecting rod assembly (43)
damaged; see pump manual
310643 or 310894.
3. Gears or drive housing damaged,
page 34.
1. Throat packing nut is loose
2. Throat packings are worn or
damaged
3. Displacement rod is worn or
damaged
1. Air in pump or hose
2. Tip is partially clogged
3. Fluid supply is low or empty
1. Air in pump or hose
2. Intake valve is leaking
3. Pump packings are worn
4. Paint is too thick
connection
WHAT TO DO
When check is not OK, refer to this column
14. Replace o-ring; see pump manual 310643
or 310894.
15. Clean intake valve; see pump manual
310643 or 310894.
16. Increase pressure; see pump manual
310643 or 310894.
17. Use larger diameter hose and/or reduce
overall length of hose. Use of more than
100 ft of 1/4 in. hose significantly reduces
performance of sprayer. Use 3/8 in. hose
for optimum performance (50 ft minimum).
1. Replace pump pin if missing. Be sure
retainer spring (31) is fully in groove all
around connecting rod; see pump manual
310643 or 310894.
2. Replace connecting rod assembly; see
pump manual 310643 or 310894.
3. Inspect drive housing assembly and gears
for damage and replace if necessary; see
pump manual 310643 or 310894.
1. Remove throat packing nut spacer.
Tighten throat packing nut just enough to
stop leakage.
2. Replace packings; see pump manual
310643 or 310894.
3. Replace rod; see pump manual 310643 or
310894.
1. Check and tighten all fluid connections.
Reduce engine speed and cycle pump as
slowly as possible during priming.
2. Clear tip; see tip guard manual 309640.
3. Refill fluid supply. Prime pump; see pump
manual 310643 or 310894. Check fluid
supply often to prevent running pump dry.
1. Check and tighten all fluid connections.
Reduce engine speed and cycle pump as
slowly as possible during priming.
2. Clean intake valve. Be sure ball seat is not
nicked or worn and that ball seats well.
Reassemble valve.
3. Replace pump packings; see pump man-
ual 310643 or 310894.
4. Thin the paint according to the supplier's
recommendations.
1. Check connections. Replace display.
Troubleshooting
311365H