374F and 390F Excavators Tool Control System Solenoid Valve (Proportional Reducing) - Calibrate - Variable Relief Valves Caterpillar

Introduction

Variable relief valves will allow for electronic control over the pressure setting to the work tool. The valves also direct oil to the return system for the one-way mode of the work tool. The valves are proportionally controlled by the machine ECM.

Required Tools

Illustration 1	g01623868
Tooling (B) 198-4240 Digital Pressure Indicator Gp

Machine Preparation

1. The following procedures must be completed before performing the calibration.

   • Perform the main control valve calibration for the ACS Attachment Valve #1. Refer to Testing and Adjusting, "Main Control Valve - Calibrate" for the machine.

   • Calibrate the main pump flow limit. Refer to Testing and Adjusting, "Solenoid Valve (Proportional Reducing) - Main Pump Flow Limit" for the Tool Control System.

2. Position the machine on level ground.

3. Stop the engine.
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   Illustration 2	g03602396
   Stop valves for high-pressure oil delivery to the work tool (typical example)

4. Close the stop valves that are mounted on each side of the stick in order to prevent oil flow to the work tool during this procedure.

5. Release pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
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   Illustration 3	g03601342
   Pump compartment (typical example) (1) Pressure tap (delivery pressure for front pump) (2) Pressure tap (delivery pressure for rear pump)

6. Attach 41,368 kPa (6,000 psi) pressure sensors to pressure taps (1) and (2) for delivery pressure of the main pumps.

7. Start the engine.

8. Place the machine controls at the following settings: engine speed dial "10" and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.

9. Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

Calibration Procedure

Note: This procedure is typical for both variable relief valves. The control input for each #1 and #2 valve calibration will differ.

Use any of the following control inputs (A) shown in Illustration 4 to calibrate "Relief Valve #1".

Illustration 4	g03366023
Electric Control Inputs for extension of the attachment control valve (LJ) Left-hand joystick (RJ) Right-hand joystick (A) Thumb wheel (Forward) (A) Switch

Use any of the following control inputs (B) shown in Illustration 5 to calibrate "Relief Valve #2".

Illustration 5	g03366372
Electric Control Inputs for "Relief Valve #2" (LJ) Left-hand joystick (RJ) Right-hand joystick (B) Thumb wheel (Backward)

1. Select a work tool that will allow for two-way flow from two pumps. The Variable Relief Valve #1 and #2 pressure setting must be set to 40000 kPa (5802 psi) for the work tool within the monitor.

   Reference: Refer to Testing and Adjusting, "Work Tool - Select" for the Tool Control System.

   Reference: Refer to Testing and Adjusting, "Work Tool Parameter - Program" for the Tool Control System.

Monitor Procedure

The following procedure will allow the user to calibrate the variable relief valves using the monitor.

1. Enter the service mode. Input the password "9992".
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   Illustration 6	g03366432

2. Select "Variable Relief Valves" from the "Calibrations" menu.
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   Illustration 7	g02283545

3. Select "Relief Valve #" for the appropriate valve from the "Variable Relief Valves" menu.

4. Press the OK key in order to start the calibration. The engine RPM will automatically increase to the equivalence of engine speed dial 10.

5. Confirm the notes on the monitor display. Set up the test conditions in accordance with the instructions. Press the OK key.
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   Illustration 8	g02283534

   Note: Refer to the previous Illustrations for the correct control input for the machine.

6. Press and hold the control input for activation of the work tool to the FULL ON position during the calibration.

   Note: Use the arrows to scroll down to view the machine "Engine Speed", "Hydraulic Oil Temperature", "Pump #1 Outlet Pressure", and "Pump #2 Outlet Pressure".

7. Use the arrows to adjust the pressure until the pressure reading is at 10000 ± 1000 kPa (1450 ± 145 psi). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

8. Press the OK key when the pressure reading holds steady at 10000 ± 1000 kPa (1450 ± 145 psi) and no more adjustment is required.
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   Illustration 9	g02283539

   Note: Refer to the previous Illustrations for the correct control input for the machine.

9. Press and hold the control input for activation of the work tool to the FULL ON position during the calibration.

   Note: Use the arrows to scroll down to view the machine "Engine Speed", "Hydraulic Oil Temperature", "Pump #1 Outlet Pressure", and "Pump #2 Outlet Pressure".

10. Use the arrows to adjust the pressure until the pressure reading is at 30000 ± 1000 kPa (4351 ± 145 psi). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

11. Press the OK key when the pressure reading holds steady at 30000 ± 1000 kPa (4351 ± 145 psi) and no more adjustment is required.
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    Illustration 10	g02283535

12. If calibration was successful and no errors occurred, the display will indicate that the calibration is complete.
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    Illustration 11	g02283543

13. The "Error" screen will be displayed on the monitor if an error occurs. The process of calibration will not be saved and the process must be restarted.

Test Procedure

Confirm the calibration using the following procedure.

Note: This procedure is typical for both variable relief valves.

1. Enter the service mode. Input the password "9992".
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   Illustration 12	g02283538

2. Select "Variable Relief Valves" from the "Device Test" menu.
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   Illustration 13	g02283546

3. Select the test for the relief valve from the "Variable Relief Valves" menu.

4. Press the OK key in order to start the test.

5. Confirm the notes on the monitor display. Set up the test conditions in accordance with the instructions. Press the OK key.
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   Illustration 14	g02283536

6. Use the arrows to adjust the pressure. Confirm the pressure with the pressure gauge.

   Note: Use the arrows to scroll down to view the machine "Engine Speed", "Hydraulic Oil Temperature", and "Pump Outlet Pressures".

Cat Electronic Technician Procedure

The following procedure will allow the user to calibrate the variable relief valves using the Cat Electronic Technician.

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Illustration 15	g02713701
Diagnostic connector for Cat Electronic Technician

1. Connect the Cat Electronic Technician to the diagnostic connector located behind the seat on the left side of the cab.
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   Illustration 16	g02713758

2. Start Cat Electronic Technician.
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   Illustration 17	g03592276

3. Select the ECM for "Machine Control".
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   Illustration 18	g03592557

4. Select "Calibrations" from the "Service" menu.
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   Illustration 19	g03593797

5. Highlight "PRV - Variable Relief Pressure Calibration" and click on the "Start" button in the lower left corner of the screen.
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   Illustration 20	g02724526

6. Select the variable relief valves to calibrate and press the "Begin" button.
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   Illustration 21	g02724528

7. Follow the instructions on the screen. Press "Next" button to continue through to the next step.

8. Press and hold the control input for activation of the work tool to the FULL ON position during the calibration.

9. Use the arrows to adjust the pressure until the pressure reading is at 10000 ± 1000 kPa (1450 ± 145 psi). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

10. Press the "NEXT" button when the pressure reading holds steady at 10000 ± 1000 kPa (1450 ± 145 psi) and no more adjustment is required.

11. Press and hold the control input for activation of the work tool to the FULL ON position during the calibration.

12. Use the arrows to adjust the pressure until the pressure reading is at 30000 ± 1000 kPa (4351 ± 145 psi). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

13. Press the "NEXT" button when the pressure reading holds steady at 30000 ± 1000 kPa (4351 ± 145 psi) and no more adjustment is required.

14. If the calibration was successful and no errors occurred, the display will indicate that the calibration is complete. Press the "Finish" button to exit or move on to the next calibration.

15. If the calibration failed, the calibration is not saved. Press the "Restart" button to try the calibration again or press the "Finish" button to exit or move on to the next calibration.

Test Procedure

Confirm the calibration using the following procedure.

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Illustration 22	g03593776

1. Select "Diagnostic Tests" from the "Diagnostics" menu.
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   Illustration 23	g03593817

2. Highlight "Variable Relief Valve Pressure Test" and click on the "Start" button in the lower left corner of the screen.
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   Illustration 24	g02727007

3. Select the test and press the "Begin" button.
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   Illustration 25	g02727008

4. Follow the instructions on the screen. Press "Start" button in the lower left corner to begin the test.

5. Use the arrows to adjust the pressure. Confirm the pressure with the pressure gauge.