Bush Hog 765H - Manual (Page 28)

Tractor
Reservoir
Note: Do not connect hoses from the backhoe con-
trol valve to the tractor hydraulic system until initial
assembly of mounting kit is complete.
1. OPEN-CENTER SYSTEM WITH LOADER
VALVE OR OTHER ACCESSORY VALVE CON-
NECTED TO THE TRACTOR HYDRAULIC SYS-
TEM:
When a loader valve or other accessory valve must
be connected to the tractor hydraulic system in addi-
tion to the backhoe control valve, a Power Beyond
Kit is required. This kit converts the backhoe valve
so that pressurized hydraulic oil can be directed to
another open-center valve for a loader or other
accessory. This allows the backhoe valve and the
other valve to be connected to the tractor hydraulic
system simultaneously, without the inconvenience of
using a flow diverting valve.
Since the Power Beyond Kit is used with open-cen-
ter tractor hydraulic systems, oil constantly flows
from the pump, through the backhoe valve and the
loader valve or other accessory valve, and then to
the reservoir. See further in this manual for instruc-
tions on proper assembly.
2. CLOSED CENTER SYSTEM: (665H &765H))
Because a closed-center system requires no flow
of oil through the backhoe control valve when the
levers are in a neutral position, the 665H & 765H
backhoes must not be connected to a closed-
center tractor hydraulic system. A PTO pump kit
is required if the tractor is to be mounted to a
tractor with closed-center hydraulic system.
IMPORTANT: Do not connect a 665H or 765H
backhoe control valve to a closed-center tractor
hydraulic system, or serious damage to backhoe
valve or tractor hydraulic system may result.
3. OPEN-CENTER SYSTEM WITH RETURN OIL
NOT REQUIRED FOR LUBRICATION - Figure 17
The pressure hose (A) on the backhoe control valve
should be connected to the pressure port of the trac-
tor’s remote couplers or directly to the tractor valve.
The return hose (B) on the backhoe control valve
should be connected directly to a port on the reser-
voir, as shown in Figure 17.
IMPORTANT: Never connect the return hose to a
tractor remote coupler which can be pressurized.
Accidental pressurization can cause serious
damage to backhoe valve.
4. OPEN-CENTER SYSTEM WITH RETURN OIL
REQUIRED FOR LUBRICATION - Figure 18
On some tractors, the return oil cannot be routed
directly to the reservoir because it is required for the
lubrication of other functions. Check this characteris-
tic with your dealer. The pressure hose (A) on the
backhoe control valve must be connected to the
pressure port of the tractor’s remote couplers or
directly to the tractor valve. The return hose (B) on
the backhoe control valve must be connected to a
surge relief valve as shown in Figure 18.
Note: The surge relief valve is not supplied with the
backhoe or mounting kit and must be ordered sepa-
rately to complete this type hydraulic hook-up.
Complete the hydraulic hook-up by connecting the
surge relief valve to the return port of tractor remote
couplers or directly to the tractor valve, and by con-
necting a hose from the TANK port of the surge
relief valve to the tractor reservoir as shown in
Figure 18. The surge relief valve is used to protect
the backhoe valve from damage caused by acciden-
tal pressurization or high back pressure build-up. If
this happens, oil will be vented from the TANK port
of the surge relief valve to the tractor reservoir to
prevent loss of vented oil.
Backhoe Valve
Coupler tip (not sup-
plied) to connect to
pressure port of oil
supply
Coupler tip (not sup-
plied) to connect to
return port of oil
supply
Surge relief valve
Tractor reservoir
Hose supplied
by customer
Figure 18
26
Figure 17
Backhoe Valve
Coupler tip (not sup-
plied) to connect to
pressure port of oil
supply
A
B
A
B