Hitachi FD2 1590 Manuel D’Utilisation

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Troubleshooting 
14
311879F
Troubleshooting
Relieve the pressure before checking or servicing 
the equipment.
Check all possible problems and causes before dis-
assembling the pump.
To reduce the risk of serious injury, whenever you are 
instructed to relieve pressure, always follow the Pres-
sure Relief Procedure
 on page 11.
PROBLEM
CAUSE
SOLUTION
Pump cycles at stall or fails to hold 
pressure at stall.
Worn check valve balls (301), seats 
(201) or o-rings (202).
Replace. See 18.
Pump will not cycle, or cycles once 
and stops.
Air valve is stuck or dirty.
Disassemble and clean air valve. See 
page 16. Use filtered air.
Check valve ball (301) severely 
worn and wedged in seat (201) or 
manifold (102 or 103).
Replace ball and seat. See page 18.
Check valve ball (301) is wedged 
into seat (201), due to overpressur-
ization.
Install Pressure Relief Valve 
(see page 10).
Dispensing valve clogged.
Relieve pressure and clear valve.
Pump operates erratically.
Clogged suction line.
Inspect; clear.
Sticky or leaking balls (301).
Clean or replace. See page 18.
Diaphragm ruptured.
Replace. See pages 19-21.
Restricted exhaust.
Remove restriction.
Air bubbles in fluid.
Suction line is loose.
Tighten.
Diaphragm ruptured.
Replace. See pages 19-21.
Loose inlet manifold (102), dam-
aged seal between manifold and 
seat (201), damaged o-rings (202).
Tighten manifold clamps (113), or 
replace seats (201) or o-rings (202). 
See page 18.
Loose diaphragm shaft bolt (107).
Tighten or replace (pages 19-21).
Damaged o-ring (108).
Replace. See pages 19-21.
Chattering - noisy operation.
Check valve balls do not seat prop-
erly/cleanly due to imbalance 
between fluid inlet and outlet line 
sizing. Noise is accentuated with 
light viscosity fluids.
Reduce size/diameter of inlet line rela-
tive to outline line. Outlet line size 
should not exceed pump size.