Troubleshooting
5-3
Part 104373
−
03
E
2015 Nordson Corporation
Corrective Action
Possible Cause
Problem
1. Pump fails to start
(contd)
Air tubing improperly routed
Check all tubing connections against
the pneumatic schematic located on
the accumulator cover and on
page 6-14 in the
Repair
section. If
the connections are correct and the
pump still will not start, then either
the double pilot valve or one of the
roller valves are faulty.
Faulty double pilot or roller valves
Disconnect the tubing from the roller
valve to the double pilot valve and
depress the roller valve actuating
lever. If no air flows through the
valve, replace it. If both roller valves
function normally, replace the double
pilot valve.
2. Pump stops during
operation
Hydraulic system blocked
Refer to corrective actions for
Problem 1.
Ice in muffler boxes or exhaust
tubes
Ice may form in the muffler boxes
and exhaust tubes when the pump is
running at high speeds with wet air or
in an unusually cold location. The air
valve will not operate if the exhaust
ports are plugged. To eliminate icing,
heat and/or dry the compressed air
supply.
3. Air leaking
continuously into
muffler
Faulty air valve
Rebuild or replace the air valve.
4. Pump strokes
irregularly or fluid
pressure fluctuates
Air leak in the siphon circuit
Leaks in the siphon system may be
checked by placing the drain rod in
water. Close the circulation valve,
open the drain valve, and operate the
pump while watching for bubbles in
the water. If bubbles occur, air is
entering the pump through the siphon
system. These are the possible leak
locations:
S
Connections in the pressure feed
system or siphon hose/rod
assembly may be leaking.
Tighten all fittings including those
at the siphon manifold. Liberally
coat all threads with pipe joint
adhesive.
S
The siphon hose may have a
small hole or crack in it. Replace
the hose.
S
The two O-rings between the
siphon manifold and the hydraulic
housings may be leaking.
Replace the O-rings.
Continued...
