19
TROUBLESHOOTING (Continued)
Problem
Sprayer draws up paint,
pressure builds up, but
drops away markedly
when gun is opened (low
performance)
Pressure fluctuation
.
Paint in hydraulic housing
Spray gun won't shut off
Cause
1. No spray tip on gun
2. Spray tip hole too large
3. Suction filter clogged
4. Gun filter plugged
5. Gun filter too fine for
coarse paint being
sprayed
6. Suction tube not firmly
tightened to inlet valve
7. Leaky suction tube
8. Leaky priming valve
9. Worn paint pump outlet
valve seat, ball, or
spring
10. Worn Inlet valve
11. Pressure control valve
worn or damaged
1. Loose suction tube at
inlet valve
2. Leaky suction tube at
inlet valve
3. Leaky or dirty priming
valve
4. Leaky, worn, or dam-
aged inlet valve
5. Outlet valve may be
stuck, dirty, or have
worn parts
6. Dirty pressure control
valve
7. Worn or damaged pres-
sure control valve
8. Pinhole in diaphragm
membrane
9. Loose oil suction tube,
causing air in hydraulic
system. Or, oil suction
tube may be partly
plugged
10. Eroded paint pump
block
11. Cracked hydraulic
housing
1. Ruptured diaphragm
membrane
1. Insufficient trigger
spring pressure on gun
2. Worn ball or diffuser
seat or gun
3. Foreign matter or paint
buildup between ball
and diffuser on gun
Remedy
1. Put on correct tip
2. Select smaller tip or try newer tip
3. Clean or replace filter
4. Clean or replace filter every 4 hours. Keep
extra filters on hand
5. Use correct filter or strain/thin paint
6. Clean connection thoroughly and tighten
7. Clean connection thoroughly and tighten
or replace tube
8. Replace valve
9. Replace defective part(s)
10. Replace valve
11. Replace valve - Take to Authorized
SprayTECH Service Center
1. Clean connection thoroughly and tighten
2. If tightening doesn’t work, replace suction
nut and adapter
3. Clean or replace valve
4. Replace valve
5. Dismantle valve. Clean or replace valve
spring first. If this doesn’t work, replace
ball
6. Take to Authorized SprayTECH Service
Center
7. Take to Authorized SprayTECH Service
Center
8. Replace diaphragm membrane
9. Clean oil suction tube if necessary and
reglue
10. Replace block
11. Replace housing
1. Take to Authorized SprayTECH Service
Center
1. Increase trigger spring pressure by
adjusting rear tension nut
2. Replace ball or diffuser or gun
3. Disassemble gun and clean