PowrCoat
17
GB
Troubleshooting
7.4
Fluid Pump
Problem
Cause
Solution
A. Pump delivers on upstroke only
or goes up slowly and down fast
(commonly called downstroke
dive).
1. Lower foot valve ball is not seating due to
trash or wear.
2. Material to viscous to siphon.
3. Air leaking in on siphon side or damaged
siphon hose. Siphon may be too small for
heavy material.
4. Upper packing nut (if applicable) is loose or
upper packings are worn.
1. Remove foot valve assembly. Clean and inspect. Test
foot valve by filling with water. If ball fails to seal the
seat, replace ball.
2. Thin material - contact manufacturer for proper
thinning procedures.
3. Tighten all connections between pump and paint
container. If damaged, replace. Switch to bigger
siphon set.
4. If tightening upper packing nut does not correct,
change upper packings.
B. Pump delivers on down stroke
only or goes up fast and down
slowly.
1. Upper ball is not seating due to trash or
wear.
2. Lower packing set is worn.
1. Check upper seat and ball with water. If ball fails to
seal seat, replace.
2. Replace packing set is worn.
C. Pump moves up and down fast,
not delivering material.
1. Material container is empty or material is
too thick to flow through the siphon hose.
2. Bottom ball stuck to foot valve seat.
3. Siphon hose is kinked or loose.
1. Refill with new material. If too thick, remove siphon
hose, immerse fluid section in material, and start
pump to prime. Add thinner to material. Change to
bigger siphon set. Open bleed valve to remove air
and restart pump.
2. Remove foot valve. Clean ball and seat.
3. Straighten.
D. Pump moves up and down
slowly when spray gun is shut
off.
1. Loose connections. Bleed valve is open
partially or bleed valve is worn. Lower
packing set is worn.
2. Upper and/or lower ball not seating.
1. Check all connections between pump and gun.
Tighten as necessary. If material is flowing from
bleed hose, close bleed valve or replace if necessary.
Should none of above be evident, replace lower
packing.
2. Reset balls by cleaning.
E. Not enough fluid pressure at
gun.
1. Spray tip is worn.
2. Compressor (air operated units only) too
small. Outlet filter or gun filter is clogged.
3. Low voltage and/or inadequate amperage.
4. Hose size or length is too small or too long.
1. Replace.
2. Clean or replace filter. Recommend proper hose size
and/or air compressor size.
3. Check electrical service. Correct as required.
4. Increase hose size to minimize pressure drop through
hose and/or reduce hose lengths.
F. Pump chatters on up or down
stroke
1. Solvent has caused upper packing to swell,
or packing is too tight.
1. Back off upper packing nut 1/4 turn (if applicable)
and restart pump. Repeat if necessary.
