Troubleshooting
B 5-4
Part 1022914G03
E
2007 Nordson Corporation
Corrective Action
Possible Cause
Problem
6. Pump continues to
operate even after
drain and circulation
valves are closed and
spray devices are
turned off
Coating material supply low, pump
siphoning air
Fill the supply container.
Leaking drain valve
Rebuild or replace the drain valve.
Leaking circulation valve
Check for a damaged or worn
circulation valve as follows:
1. Shut off the pump air supply.
2. Open the drain valve to relieve
the hydraulic pressure.
3. Close the drain valve.
4. Immerse the siphon rod in coating
material.
5. Disconnect the return hose from
the circulation valve.
6. Connect an air hose to the
circulation valve in place of the
return hose.
7. Apply compressed air to the
circulation valve. If air bubbles
from the siphon rod, replace the
circulation valve needle and seat.
Leaking ball check valve
Rebuild the ball check valves.
7. Pump does not stroke
when circulation
valve is opened
Clogged circulation valve, or
blockage in system
Open the circulation valve fully, then
close it partially. If the problem
continues, flush the system with a
compatible cleaning solution. Refer
to problem 1.
No compressed air supply, or air
pressure is too low
Check the air supply at the drop-leg
drain valve. Make sure the regulator
is working correctly.
8. Solvent chamber
overflows often
Upper packings worn
Shut off pump, relieve hydraulic
pressure, and tighten solvent cup
1
/
8
to
1
/
4
turn. If leaking continues,
replace the packings. Upper and
lower packings should be replaced at
the same time.
Continued...
