Graco Mark V Premium Repair Manual page 11

TYPE OF PROBLEM
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 oper-
ates
3A2333B
WHAT TO CHECK
If check is OK, go to next check
Displacement pump pin damaged or
missing; see pump manual.
Connecting rod assembly damaged;
see pump manual.
Gears or drive housing damaged,
page 27.
Throat packing nut is loose
Throat packings are worn or
damaged
Displacement rod is worn or
damaged
Air in pump or hose
Tip is partially clogged
Fluid supply is low or empty
Air in pump or hose
Intake valve is leaking
Pump packings are worn
Paint is too thick
Display is damaged or has bad
connection
WHAT TO DO
When check is not OK, refer to this column
Replace pump pin if missing. Be sure retainer
spring is fully in groove all around connecting
rod; see pump manual.
Replace connecting rod assembly; see pump
manual.
Inspect drive housing assembly and gears for
damage and replace if necessary; see pump
manual.
Remove throat packing nut spacer. Tighten
throat packing nut just enough to stop leakage.
Replace packings; see pump manual.
Replace rod; see pump manual.
Check and tighten all fluid connections. Cycle
pump as slowly as possible during priming.
Clear tip; see pump manual.
Refill fluid supply. Prime pump; see pump man-
ual. Check fluid supply often to prevent running
pump dry.
Check and tighten all fluid connections. Cycle
pump as slowly as possible during priming.
Clean intake valve. Be sure ball seat is not
nicked or worn and that ball seats well. Reas-
semble valve.
Replace pump packings; see pump manual.
Thin the paint according to supplier recommen-
dations.
Check connections. Replace display.
Troubleshooting
11