Great Plains P17400G Operator Manual - Manual (Page 29)

29 Single Press
Operating Instructions
5. Servicing and Maintenance
5.8 To Adjust the System
Pressure
A low oil flow should be used,
i.e., tractor tickover or low flow
selected.
The wing circuit is controlled by an
overcentre valve which positively
locks oil flow until pressurised by
the tractor. System pressure can
be retained in the circuit even
after depressurisation of the
tractor quick release couplings.
Exercise extreme care when
checking the valve or circuits, and
under no circumstances attempt
to adjust or loosen fittings without
prior reference to your authorised
dealer, and detailed maintenance
instructions.
In some cases it may be necessary to
adjust the wing fold circuit pressure. Higher
pressure will cause the wing tips to dig in
causing the centre of the machine to lift it
out. Too little pressure will cause the wing
tips to lift out & the centre of the machine
to dig in. When towing another implement
behind the Single Press, the pressure may
need increasing to compensate.
In all cases, regardless of tractor make,
adjustment should start from minimum
pressure and gradually increase up to
desired pressure.
Valve adjustment should be
carried out in small increments. A
full turn of the valve will cause a
significant change in the operation
of the machine.
If the system needs adjusting, fully raise the
machine, partially fold the wings & hold them
in this position. To adjust the pressure utilise
valve A (shown in Fig. 5.01). Unscrew the
adjusting screw:
• Turning adjuster clockwise increases
pressure at wing tips.
• Turning adjuster anti-clockwise
decreases pressure at wing tips.
Once the desired setting is achieved lock
the valve.
Only valve A should be adjusted. All
other valves are set at the factory
and should not be tampered with.
Fig. 5.01: Adjusting system pressure
A
FRONT OF MACHINE