Type of malfunction
Hydraulic motor stuck in
the upper position.
Low pressure.
The piston rod moves
correctly in the downward
stroke, but the upward
stroke is sluggish.
The outside of the hydraulic
motor is very hot.
Low pressure.
The outside of the hydrau-
lic motor becomes very hot
when stroking upward and
downward.
9.3 Material feed pump
Type of malfunction
A sufficient amount of coa-
ting material is ejected only
with an upward stroke, or
upward motion of the piston
rod is slow and downward
motion is fast
A sufficient amount of coa-
ting material is ejected only
with a downward stroke, or
downward motion of the pi-
ston rod is slow and upward
motion is fast.
HC 35 G • HC 45 G • HC 55 G
Possible cause
Reversing valve is stuck.
Pressure spring on valve
rod is broken.
Pressure spring stop on
valve rod is broken.
Air in the hydraulic mo-
tor.
Air in the material feed
pump.
Faulty piston packing in
hydraulic motor.
Piston rod is broken.
Middle O-ring on rever-
sing valve is faulty.
Packings in the material
feed pump are worn.
Possible cause
Inlet valve is leaky due to
impurities or wear.
Coating material viscosity is
too high, preventing it from
being sucked up.
Outlet valve leaky.
Lower packing is worn.
g
Measure for elimination of malfunction
Problem to be solved by Wagner personnel.
Problem to be solved by Wagner personnel.
Problem to be solved by Wagner personnel.
Turn back pressure regulating knob.
Vent air at low pressure during a 5 – 10 minute
endurance run. Do not let the material feed pump run
dry.
Check for leaks:
• Loose connections on hydraulic oil tank
• Loose connections on the hydraulic oil pump
• Loose hydraulic oil hose connections
• Level of oil in hydraulic tank is too low
Ball valve on the material feed pump – lever position
vertical. Screw out sealing screw on hydraulic motor.
Press down reversing valve on hydraulic motor. Remo-
unt sealing screw. Start unit. Prevent the material feed
pump from sucking up air.
Problem to be solved by Wagner personnel.
Problem to be solved by Wagner personnel.
Problem to be solved by Wagner personnel.
Replace
Measure for elimination of malfunction
Clean and check the inlet valve housing. Insert ball
and fill with water; if leaky, replace ball.
Thin out according to the manufacturer's instructions.
Dismantle and check outlet valve seat.
Insert ball and fill with water; if leaky, replace ball.
Replace
Remedy in case of faults
43