Bush Hog 965H, 865H manual Closed Center System 665H &765H

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.

Figure 17

Backhoe Valve

Coupler tip (not sup- plied) to connect to pressure port of oil supply

A

Tractor

Reservoir

B

Figure 18

Backhoe Valve

Coupler tip (not sup- plied) to connect to pressure port of oil supply

A

Coupler tip (not sup- plied) to connect to return port of oil supply

B Surge relief valve

Tractor reservoir

Hose supplied by customer

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