DALBO CULTITRAIL 500, Manual, Page: 14 / 36

CULTITRAIL
Page 14
Hydraulics for levelling board and wheel frame
Bleeding the system
If the machine has not been used for some time, air can get into the system. This can cause one or both
side sections to not reach the same working depth as the centre section. Bleed the system by moving
the spacer blocks (E) on both cylinders to the side, so that the cylinder can fully retract. The cylinders
are designed to allow the oil to pass over the ram through a channel when fully retracted. The harrow is
then fully lowered using the tractor hydraulic system. Hold the handle in lower position (not flow posi-
tion!) for a several minutes after the cylinder has fully retracted, even if using the tractor's over-
pressure valve. The system will now be bled.
The hydraulic cylinders for the front levelling board are linked in the same way. Use the same proce-
dure for bleeding.
Fig. 4
The hydraulic cylinders (A) are linked in series with the cor-
responding wheel frame cylinder on the side section. When
the wheel frame is raised, the tractor pumps oil to (B) the
centre cylinders. The oil which then flows out of (C) is linked
to (B) on the side section cylinder. As the cylinders have
free ram shafts (D), the amount of oil moved on each side of
the ram is identical for any given movement. This ensures
that the side cylinders move to exactly the same extent as
those in the centre. A depth stop is therefore only neces-
sary on the two centre cylinders. The side cylinders auto-
matically maintain the same working depth.
A
E
D
B
C