Graco Mark VII Paint Sprayer User Manual


 
Troubleshooting
332916C 25
Pump output is low Pump rod damage Repair pump. See pump manual.
Low stall pressure Turn pressure knob fully clockwise. Make sure
pressure control knob is properly installed to
allow full clockwise position. If problem per-
sists, replace pressure transducer.
Piston packings are worn or dam-
aged
Replace packings; see pump manual.
O-ring in pump is worn or damaged Replace o-ring; see pump manual.
Intake valve ball is packed with mate-
rial
Clean intake valve; see pump manual.
Pressure setting is too low Increase pressure; see pump manual.
Large pressure drop in hose with
heavy materials
Use larger diameter hose and/or reduce overall
length of hose.
Check to see if Amp switch (10/16 or
15/20) is on low setting. Make sure
circuit is able to provide high setting.
Switch to 16A or 20A setting. Change to circuit
that provides 16A or 20A. Change to less
loaded circuit.
Motor runs but pump does
not stroke
Displacement pump pin damaged or
missing; see pump manual.
Replace pump pin if missing. Be sure retainer
spring is fully in groove all around connecting
rod; see pump manual.
Connecting rod assembly damaged;
see pump manual.
Replace connecting rod assembly; see pump
manual.
Gears or drive housing damaged. Inspect drive housing assembly and gears for
damage and replace if necessary; see pump
manual.
Excessive paint leakage
into throat packing nut
Throat packing nut is loose Remove throat packing nut spacer. Tighten
throat packing nut just enough to stop leakage.
Throat packings are worn or dam-
aged
Replace packings; see pump manual.
Displacement rod is worn or dam-
aged
Replace rod; see pump manual.
Fluid is spitting from gun Air in pump or hose Check and tighten all fluid connections. Cycle
pump as slowly as possible during priming.
Tip is partially clogged Clear tip; see Operation manual.
Fluid supply is low or empty Refill fluid supply. Prime pump; see pump man-
ual. Check fluid supply often to prevent running
pump dry.
TYPE OF PROBLEM
WHAT TO CHECK
If check is OK, go to next check
WHAT TO DO
When check is not OK, refer to this column