Graco Mark X User Manual

Troubleshooting
3A6342A 37
Pump output is low
Spray tip worn Follow Pressure Relief Procedure, page 19, then
replace tip. See your separate Spray Gun or tip manual.
Spray tip clogged Refer to Clear Spray Tip Clog, page 26
Paint supply is empty Refill and reprime pump.
Suction Tube strainer clogged Remove and clean, then reinstall.
Intake valve ball and piston ball are
not seating properly
Remove intake valve and clean. Inspect balls and seats
for nicks; replace if necessary; see pump manual.
Strain paint before using to remove particles that could
clog pump.
Sprayer filter or Spray Gun filter is
clogged or dirty.
Clean or replace filter.
Prime valve leaking Follow Pressure Relief Procedure, page 19. Replace
prime valve.
Pump is worn. Service pump; see pump manual.
Pump throat packings are worn. Tighten packing nut/wet cup. If leakage continues,
replace packings; see pump manual. Also check piston
valve seat for hardened paint or nicks and replace if
necessary. Tighten packing nut/wet-cup.
Intake valve ball is packed with
material
Clean intake valve; see pump manual.
Pressure setting is too low Turn Pressure Control Knob clockwise to increase
pressure.
Material is too thick for a small
diameter Hose, or Hose is too long.
Use larger diameter Hose and/or reduce overall length
of Hose.
Amp switch is on low setting. (10A or
15A setting)
Switch to 16A or 20A setting.
Fluid is spitting from Spray Gun
Tip is partially clogged Refer to Clear Spray Tip Clog, page 26.
Material supply low, or air was not
properly purged during priming.
Refill fluid supply. Refer to Fill Pump (Prime Pump),
page 21. Then Fill Spray Gun and Hose, page 22.
Check fluid supply often to prevent running pump dry.
Pump is difficult to prime
Intake valve is stuck to seat. Remove foot valve. Clean and inspect intake valve.
Suction tube o-ring on foot valve is
damaged or missing.
Replace Suction Tube o-ring.
Air in pump Refer to Fill Pump (Prime Pump), page 21. Then Fill
Spray Gun and Hose, page 22.
Intake valve is leaking Clean intake valve. Be sure ball seat is not nicked or
worn and that ball seats well. Reassemble valve.
Pump packings are worn Replace pump packings; see pump manual.
Motor does not run
Pressure Control Knob is set too low Increase pressure by turning Pressure Control Knob
clockwise.
Spray tip clogged Refer to Clear Spray Tip Clog, page 26.
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.
Problem Cause Solution

Graco Mark X Specifications

General

Brand	Graco
Model	Mark X
Category	Paint Sprayer
Language	English