Bush Hog 2175 - Manual (Page 35)

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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: (2165)
Because a closed-center system requires no flow of
oil through the backhoe control valve when the
levers are in a neutral position, the 2165 backhoe
must not be connected to a closed-center tractor
hydraulic system. A PTO pump kit is required if
the backhoe is to be mounted to a tractor with a
closed-center hydraulic system.
IMPORTANT: Do not connect a 2165 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 19
The pressure hose (A) should be connected from the
pressure port at the backhoe bulkhead connection to
the pressure port of the tractor remote couplers or
directly to the tractor valve. The return hose (B)
should be connected from the tank (return) port at
the backhoe bulkhead connection directly to a port
on the reservoir, as shown in Figure 19.
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 20
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) must be
connected from the pressure port at the backhoe
bulkhead connection to the pressure port of the trac-
tor’s remote couplers or directly to the tractor valve.
The return hose (B) must be connected from the
tank (return) port at the backhoe bulkhead connec-
tion to a surge relief valve as shown in Figure 20.
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 TANK port of the surge relief
valve to the tractor reservoir as shown in Figure 20.
The surge relief valve is used to protect the backhoe
valve from damage caused by accidental pressuriza-
tion 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.
Figure 19 Backhoe Valve
Tank
Pressure
Backhoe Bulkhead
Connectors
B
A
Hoses Supplied
By Customer
To Tractor Reservoir
Tractor
Coupler Tip
Figure 20
Backhoe Valve
Tank
Pressure
Backhoe Bulkhead
Connectors
Hoses Supplied
By Customer
B
A
To Tractor Reservoir
Tractor
Coupler Tips
To Return Port
Of Oil Supply
To Pressure Port
Of Oil Supply
To Pressure Port
Of Oil Supply