416E Backhoe Loader Hydraulic and Steering System Relief Valve (Steering) - Test and Adjust Caterpillar

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Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine. To prevent possible injury, perform the procedure that follows before testing and adjusting the brake system.

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Escaping fluid under pressure, even a pinhole size leak, can penetrate body tissue, causing serious injury, and possible death. If fluid is injected into your skin, it must be treated immediately by a doctor familiar with this type of injury. Always use a board or cardboard when checking for a leak.

Note: The Relief Valve for the steering is not adjustable. The priority valve for the steering is not adjustable.

General Information

The Testing and Adjusting, "Hydraulic Pump - Test and Adjust" should be completed before performing this test. This will ensure that the flow compensator and the pressure compensator are set correctly.

Illustration 1	g01779713
(1) Hydraulic pump (2) System pressure tap

The system pressure tap (2) is located at the bottom of the pump. Access is gained from the bottom of the machine.

Illustration 2	g01779715

The load sensing valve for the steering (3) is located on the metering pump (4). The load sensing valve for the steering limits the signal pressure from the steering system that acts on the priority valve. The load sensing valve for the steering drains the signal pressure to the tank when the pressure rises above the relief valve setting.

Stall Test for the Steering

Note: Perform the Margin Pressure test first.

1. Install one 6V-4143 Coupler to each end of each the 177-7860 Hose Assembly .

2. Install one 8T-0860 Pressure Gauge with a range of 0 to 40,000 kPa (0 to 5800 psi) to the hose. Install the hose to the system pressure tap (2) .

3. Engage the parking brake. Start the engine. Keep the machine in NEUTRAL.

4. Run the engine at 1200 RPM.

5. Turn the steering to the stops in both directions for three cycles. Turn the Steering to the right to the stop. Note the indication on the gauge. The correct pressure setting for the stall of the steering is 16800 kPa to 19700 kPa (2440 psi to 2860 psi).

   Note: There may be air in the signal network, if there is a hesitation before reaching the relief pressure. Purge the signal lines of the air.

6. If the pressure for the stall of the steering is correct, then go to Step 7. If the pressure is not correct, then replace the metering pump.

7. Turn off the engine and remove the test equipment.