Introduction
Pump discharge pressures are known values that can be found under specific conditions. The first condition is low pressure standby. The second condition is the high pressure stall. The third condition is a test of margin pressure during operation of the blade.
The high pressure stall test indicates if the pressure compensator needs to be adjusted. The margin pressure test and/or the low pressure standby test indicates if the flow compensator needs to be adjusted.
Required Tools
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| Illustration 1 | g01300562 |
Tooling (A) | |
 | |
| Illustration 2 | g01300564 |
Tooling (B) | |
| Required Tools | |||
|---|---|---|---|
| Item | Part Number | Part Description | Qty |
| A | 6V-7830 | Tetragauge Group | 1 |
| 210-5530 (1) | Coupler | 1 | |
| B | 1U-5796 | Pressure Differential Tool Gp | 1 |
| 210-5530 (2) | Coupler | 1 | |
| ( 1 ) | 210-5530 Coupler must be installed on Tetragauge Group before attaching to the machine. |
| ( 2 ) | 210-5530 Coupler must be installed on Pressure Differential Gauge Group before attaching to the machine. |
| Required Tools from the 1U-5796 Pressure Differential Tool Gp | ||||
| Tooling | Item | Part Number | Part Description | Qty |
| B | B1 | 177-7861 | Hose As | 1 |
| B2 | 6V-4143 | Quick Connect Coupler | 4 | |
| B3 | 6V-3965 | Fitting As | 3 | |
| B4 | 6V-4144 | Quick Connect Coupler | 1 | |
| B5 | 8T-0861 | Pressure Gauge 60000 kPa (8600 psi) |
1 | |
| B6 | 8C-8431 | Tee | 1 | |
| B7 | 1U-5793 | Oil Filter Pressure Differential Gauge Gp | 1 | |
| B8 | 6V-0484 | O-Ring Adapter | 1 | |
| B9 | 177-7861 | Hose As | 1 | |
Test Procedure (High Pressure Stall)
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| Illustration 3 | g01318344 |
(1) Implement signal pressure (3) Implement pump discharge pressure | |
- Lower all attachments to the ground.
- Stop the engine. Move the hydraulic control levers to all positions several times so that the pressure in the hydraulic system is released.
- Attach Tooling (A) to pressure tap (3) .
Note: Make sure that the coupler that is installed on Tooling (A) is 210-5530 Coupler. Failure to use 210-5530 Coupler may cause damage to the fitting.
- Start the engine and run the engine at HIGH IDLE.
- Warm the hydraulic oil to 65° ± 10°C (150° ± 18°F).
- Move the control lever in order to initiate a stall condition in the tilt cylinder. Do not keep the control lever in a stalled condition for more than 10 seconds. Do not return to a stalled condition within 30 seconds of the prior stalled condition.
- Pressure reading must be 25000 ± 350 kPa (3626 ± 50 psi).
Note: If the pressure reading is too high or too low, perform the steps in "Adjustment Procedure (Compensator Valve)".
Test Procedure (Margin Pressure)
| | |
| Illustration 4 | g01318344 |
(1) Implement signal pressure (3) Implement pump discharge pressure | |
- Lower all attachments to the ground.
- Stop the engine. Move the hydraulic control levers to all positions several times so that the pressure in the hydraulic system is released.
- Connect hose (B1) to pressure tap (3). Connect hose (B9) to signal pressure tap (1) .
Note: Make sure that the coupler that is installed on tooling (B) for pressure tap (3) is 210-5530 Coupler. Failure to use 210-5530 Coupler may cause damage to the fitting.
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| Illustration 5 | g00838729 |
- Start the engine and run the engine at HIGH IDLE.
- Warm the hydraulic oil to 65° ± 10°C (149° ± 18°F).
- Move the bulldozer control lever to a position between the HOLD and RAISE positions. Read the pressure on the gauge while the blade is still rising. This is the margin pressure or the difference between pump discharge pressure and the signal pressure from the control valve. The margin pressure should be 1700 ± 100 kPa (247 ± 15 psi).
- If margin pressure is not correct, perform the steps in "Adjustment Procedure (Flow Compensator Spool)".
Note: Recheck the margin pressure after the flow compensator spool has been adjusted.
Test Procedure (Low Pressure Standby)
| | |
| Illustration 6 | g01318344 |
(1) Implement signal pressure (3) Implement pump discharge pressure | |
- Lower all attachments to the ground.
- Stop the engine. Move the hydraulic control levers to all positions several times so that the pressure in the hydraulic system is released.
- Attach tooling (A) to pressure tap (3) .
Note: Make sure that the coupler that is installed on tooling (A) is 210-5530 Coupler. Failure to use 210-5530 Coupler may cause damage to the fitting.
- Start the engine and run the engine at HIGH IDLE.
- Warm the hydraulic oil to 65° ± 10°C (149° ± 18°F).
- Leave all control levers in the HOLD position.
- Low pressure standby will be between zero and 200 kPa (29 psi) above margin pressure. Margin pressure should be 1700 ± 100 kPa (247 ± 15 psi).
- Do not make adjustments to the pump output only because of the results of this test. Instead, if the results are not acceptable, perform the steps in "Test Procedure (Margin Pressure)".
Adjustment Procedure (Compensator Valve)
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| Illustration 7 | g00840084 |
Compensator Valve (4) Flow Compensator Spool (5) Locknut (6) Adjustment screw for the Flow Compensator (7) Nut (8) Pressure Compensator Spool (9) Locknut (10) Adjustment screw for the Pressure Compensator (11) Nut | |
Adjustments to the pressure compensator valve can be made on the machine.
- Lower all attachments to the ground.
- Stop the engine. Move the hydraulic control levers to all positions several times so that the pressure in the hydraulic system is released.
- Remove nut (11) .
- Loosen locknut (9). Maintain the position of adjustment screw (10) .
- Turn adjustment screw (10) clockwise in order to increase the pressure setting. Turn adjustment screw (10) counterclockwise in order to decrease the pressure setting.
Note: Turn adjustment screw (10) counterclockwise past the desired pressure setting. Then, turn adjustment screw (10) clockwise to the correct pressure setting. This method of adjusting the pressure setting eliminates any movement in the threads.
- Tighten locknut (9) to a torque of 21 N·m (15 lb ft).
Note: Do not allow adjustment screw (10) to rotate when locknut (9) is tightened.
- Install nut (11). Tighten nut (11) to a torque of 21 N·m (15 lb ft).
- Repeat "Test Procedure (High Pressure Stall)" in order to verify that the pressure setting is 25000 ± 350 kPa (3626 ± 50 psi).
Adjustment Procedure (Flow Compensator Spool)
Note: Adjustments to the flow compensator valve can be made on the machine.
| | |
| Illustration 8 | g00840084 |
Compensator Valve (4) Flow Compensator Spool (5) Locknut (6) Adjustment screw for the Flow Compensator (7) Nut (8) Pressure Compensator Spool (9) Locknut (10) Adjustment screw for the Pressure Compensator (11) Nut | |
- Lower all attachments to the ground.
- Stop the engine. Move the hydraulic control levers to all positions several times so that the pressure in the hydraulic system is released.
- Remove nut (7) .
- Loosen locknut (5). Maintain the position of adjustment screw (6) .
- Turn adjustment screw (6) clockwise in order to increase the pressure setting. Turn adjustment screw (6) counterclockwise in order to decrease the pressure setting.
Note: Turn adjustment screw (6) counterclockwise past the desired pressure setting. Then, turn adjustment screw (6) clockwise to the correct pressure setting. This method of adjusting the pressure setting eliminates any movement in the threads.
- Tighten locknut (5) to a torque of 21 N·m (15 lb ft).
Note: Do not allow adjustment screw (6) to rotate when locknut (5) is tightened.
- Install nut (7). Tighten nut (7) to a torque of 21 N·m (15 lb ft).
- Repeat "Test Procedure (Low Pressure Standby)" and "Test Procedure (Margin Pressure)".