
McHale
991 High Speed
Round Bale Wrapper
77
13.1.5 Control box
13.1.6 Hydraulics
Cut & hold leaks back
slowly
Seals weak in the gearbox Replace seals
Loose hydraulic fitting on
gearbox
Tighten hydraulic fitting
Cut & hold and tip-up
cycles very slow
Tractor pressure too low
Ensure tractor has 150 bar
pressure
Faulty pressure switch
(electronic machines)
Replace pressure switch
Relief valve set too low
Set to 150 bar pressure
Cut & hold not cutting film
Damaged blade or knife
guard still closed
Replace blade and/or
open knife guard
Symptom
Reason
Solution
Control box not counting
Sensor damaged
Locate and replace
Magnet broken
Locate and replace
Sensor - magnet
clearance
Adjust sensor approx.
10-15 mm from magnet
Faulty control box
Replace control box
“LOW BATT” appears on
the control box
Supply voltage too low
Check battery and
charging system
Only half the number of
actual rotations is
displayed on the control
box
One set of magnets
missing
Replace the missing set of
magnets
Control box will not switch
to “auto” setting
Loom not connected to the
box
Connect loom
Symptom
Reason
Solution
Hydraulics under pressure
when the wrapper is idle
Valve set to closed centre
on open centre system
Change the setting
Hydraulic system vibrating Incorrect valve setting for
the tractor being used
Set the valve to suit the
tractor hydraulic system
being used
Symptom
Reason
Solution