Problem
1.
Pump not Stroking
2.
Pump Leaking
Adhesive
3.
Pump Strokes
Erratically
E 2011 Nordson Corporation
Table D‐1 Pump Diagnostics
Possible Cause
Air valve dirty or damaged
Valve sleeve O‐rings damaged or
deteriorated
Air leaking from between the cylinder
head and the air cylinder or between
the air cylinder and the pump frame
Piston cups damaged
Shifter fork damaged, slipped out of
position on piston, installed upside
down, or magnets loose
Magnets on actuator assembly loose
Piston damaged or has char buildup
O‐ring and/or pump seal deteriorated
or damaged
O‐rings on cross‐over tubes or
between the pump and manifold
damaged or deteriorated
Siphon ball, seat and/or cage is
damaged, deteriorated, or has char
buildup
Pressure ball and/or seat has char
buildup or is scratched or pitted
Piston has char buildup
Pump body dirty
SP Pump Diagnostics and Repair
Corrective Action
Remove the Valve Spool and Sleeve
Remove the Valve Spool and Sleeve
Remove The Actuator and the Air
Cylinder Assembly
Remove the Piston Cups
Removing the Shifter Fork
Remove the Magnetic Actuator Assembly
Remove the Lower Ball Seat Assembly
and the Piston
Remove the Pump O‐ring and the Pump
Seal
Removing the Pump from the Melter
Disassemble the Lower Ball Seat and
Pressure Ball Assemblies
Disassemble the Lower Ball Seat and
Pressure Ball Assemblies
Remove the Lower Ball Seat Assembly
and the Piston
Remove the Lower Ball Seat Assembly
and the Piston
D‐5
Part 1024496_05