D6N Track-Type Tractor Caterpillar

Make sure that no one is endangered before you lower the attachments.

The Procedure Before The Accumulator Purges

The operator presence switch must be ON.

1. Place the hydraulic lockout switch in the UNLOCK position.

2. Turn the engine start switch to the ON position.

3. Leave the key in the ON position.

4. Slowly move the implement control for the bulldozer blade into the LOWER position in order to lower the blade to the ground.

5. Slowly move the implement control for the ripper into the LOWER position in order to lower the ripper to the ground.

The Procedure After The Accumulator Purges

If the engine starts, perform the above procedure.

If the engine does not start, perform the following procedure.

After the engine has been stopped for a longer period, the control levers will not lower the implements to the ground.

There are two mechanical methods that can be used to lower the attachments.

Accumulator Charging

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Illustration 1	g02415034

1. Open the rear access cover on the left side of the machine.
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   Illustration 2	g02416756

2. Remove the protective cap from pressure tap (1). This pressure tap is for the remote pilot supply.

   The first method is explained in steps 2a through 2e.

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   Illustration 3	g01059993
   (A) Changed components location (B) 3P-2233 Coupler Assembly (not shown) (2) Relief valve (3) Handle (4) Bypass valve (5) Brake release pump

   1. Use an FT1845 FT1845 Brake Release Pump (5) and 3P-2233 Coupler Assembly (B) to control oil pressure to the accumulator.

   2. Remove the components that are indicated by shaded area (A). Plug the pressure hose at the connection "3/8 - 18 NPT".

   3. Turn the handle of the bypass valve (5) to the closed position.

   4. While you are pumping the handle (4), observe the opening pressure of the relief valve (3).

   5. Adjust the opening pressure of the relief valve. Set the pressure to 3100 ± 70 kPa (450 ± 10 psi).

3. The second method is explained in steps 3a through 3e.

   1. Charge the pilot hydraulic system at the pressure tap for remote pilot supply (1) in order to lower the implements.

   2. Connect 3P-2233 Coupler Assembly (B) to 9J-6190 Adapter Union on the pump pressure hose .

   3. Turn the bypass valve handle (4) to the CLOSED position.

   4. Initially, rapidly move the pump handle. This action will produce a large volume of oil flow.

   5. Fully seat the quick connector seal. Seating the seal is evident by a sudden rise in the oil pressure. When the seal is properly seated, the pressure rises to the maximum.

      Note: The hydraulic system can now be pressurized.

1. Close the access door.

2. Place the hydraulic lockout switch in the UNLOCK position.

3. Turn the engine start switch key to the ON position.

4. Leave the key in the ON position.

5. Slowly move the implement control for the bulldozer blade in the LOWER position in order to lower the blade to the ground.

Manual Lowering of the Dozer Blade

If there is no electrical power or the accumulator could not be charged, the dozer blade cannot be lowered with the implement control. The dozer blade must be lowered manually.

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Illustration 4	g02416777

1. The control valve for the bulldozer blade is located behind the side plate underneath the right armrest. Remove the side plate.
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   Illustration 5	g02416938

2. Slowly turn the screw (1) on the relief valve in a counterclockwise direction. The dozer blade will lower to the ground.

3. Slowly turn the screw on the relief valve in a clockwise direction. Turn the screw until the stem bottoms out in the hole. Tighten the screw in order to lock down the screw. This procedure may change the setting for the relief valve. Consult your Caterpillar dealer for more information on checking the setting of the relief valve.

4. Make any necessary repairs before you operate the machine.

5. Install the side plate.

Manual Lowering of the Ripper

1. The control valve for the ripper is located behind the side plate underneath the right armrest. Remove the side plate.
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   Illustration 6	g02418662

2. Slowly turn valve (2) counterclockwise until the ripper is lowered to the ground.

3. Once the ripper is resting on the ground, turn the valve clockwise until the valve stops.

4. Consult your Caterpillar dealer for more information on checking the hydraulic circuit for the ripper.

5. Install the side plate.