349E, 349F and 352F Excavators and 349E MHPU Mobile Hydraulic Power Unit Tool Control System Caterpillar

Introduction

Negative flow control pressure flows to the regulators at the drive pump and the idler pump in order to control the output flow of the pumps. The proportional reducing valve for negative flow control regulates the amount of pilot pressure from the pilot pump and signal oil pressure from the main control valve that flows into the regulators of the main pumps. The proportional reducing valves for negative flow control are controlled by the machine ECM.

Required Tools

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

Illustration 2	g03626876
Tooling (D) (Flow meter tool layout)

Machine Preparation

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

   • Set the pilot pressure to the specifications in Testing and Adjusting, "Relief Valve (Pilot) - Test and Adjust" for the machine.

   • Calibrate the power shift pressure. Refer to Testing and Adjusting, "Solenoid Valve (Proportional Reducing) - Calibrate (Power Shift Pressure)" for the machine.

   • Calibrate the attachment valves. Refer to Testing and Adjusting, "Solenoid Valve (Proportional Reducing) - Calibrate (Attachment Valves)" for the Tool Control System.

2. Position the machine on level ground.

3. Stop the engine.
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   Illustration 3	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 loss.

5. Release pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
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   Illustration 4	g03642401
   Flow meter tool layout (stop valves on stick) (1) Left stop valve (2) Right stop valve

6. Install the following tools in accordance with the flow meter tool layout. Refer to Illustration 4.

7. Open the stop valves that are mounted on each side of the stick.
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   Illustration 5	g03626840
   Pump compartment (3) Pressure tap (delivery pressure for drive pump) (4) Pressure tap (delivery pressure for idler pump)

8. Attach 41,368 kPa (6,000 psi) pressure sensors to pressure taps (3) and (4) for delivery pressure of the main pumps.

9. Start the engine.

10. 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.

11. Increase the hydraulic oil temperature to 50° ± 10°C (122° ± 18°F).

Calibration Procedure

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To prevent personal injury or equipment damage from failure of the hydraulic test equipment or associated circuit components because of blocked pump flow, make sure that the test equipment valves are fully open before starting the engine.

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To prevent personal injury and/or equipment damage from failed lines or components while the hydraulic test equipment is returned to the open flow position, slowly open the hydraulic test equipment valve while monitoring the pump flow. If pump flow does not increase as the valve is opened, shut the engine off and determine what is preventing the pump from upstroking.

Note: This procedure is typical for both proportional reducing valves for pump flow limit.

Use any of the following control inputs (A) shown in Illustration 6 and 7 to calibrate the flow limit valves.

Illustration 6	g02333296
Electric Control Inputs for extension of the attachment control valves (LJ) Left-hand joystick (RJ) Right-hand joystick (A) Thumb wheel (Forward) (A) Switch (EP) Electric foot pedal (A) Pedal (Forward) (FS) Foot switch (A) Foot switch (ON)

Illustration 7	g03082697
Hydraulic Control Inputs for extension of the attachment control valves (HP) Hydraulic foot pedal (A) Pedal (Forward)

1. Select a work tool that will allow for two-way flow from two pumps. The Variable Relief Valve #1 (Parameter #9) 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 flow limit valves using the monitor.

1. Enter the service mode. Input the password "9992".
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   Illustration 8	g02276293

2. Select "Main Pump Flow Limit" from the "Calibrations" menu.
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   Illustration 9	g02280293

3. Select "NFC (Flow Meter Method)" for the appropriate valve from the "Main Pump Flow Limit" 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 10	g02283033
   Portable hydraulic tester (flow meter) (5) Load valve

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   Illustration 11	g02346336

   Note: Refer to Illustration 6 for the control input.

6. Press and hold the control input for activation of the work tool to the FULL ON position during 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. Set the main pump pressure using load valve (5) on the flow meter to 16000 ± 500 kPa (2321 ± 73 psi).

8. Use the arrows to adjust the flow until the flow reading for the flow limit valve is at 150 ± 2 L/min (39.6 ± 0.5 gpm). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

9. Repeat Steps 7 and 8 until the flow meter reads 150 ± 2 L/min (39.6 ± 0.5 gpm) and the pressure gauge reads 16000 ± 500 kPa (2321 ± 73 psi).

10. Press the OK key.
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    Illustration 12	g02346337

    Note: Refer to Illustration 6 for the control input.

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

12. Set the main pump pressure using load valve (5) on the flow meter to 16000 ± 500 kPa (2321 ± 73 psi).

13. Use the arrows to adjust the flow until the flow reading for the flow limit valve is at 250 ± 2 L/min (66 ± 0.5 gpm). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

14. Repeat Steps 12 and 13 until the flow meter reads 250 ± 2 L/min (66 ± 0.5 gpm) and the pressure gauge reads 16000 ± 500 kPa (2321 ± 73 psi).

15. Press the OK key.
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    Illustration 13	g02281293

16. If calibration was successful and no errors occurred, the display will indicate that the calibration is complete.
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    Illustration 14	g02281435

17. 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 and specifications. Refer to Table 2 for the load pressure and flow specifications.

Note: This procedure is typical for both proportional reducing valves for pump flow limit.

1. Enter the service mode.
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   Illustration 15	g02283177

2. Select "Main Pump Flow Limit" from the "Device Test" menu.
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   Illustration 16	g02283214

3. Select the test for the appropriate valve from the "Main Pump Flow Limit" 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 17	g02283033
   Portable hydraulic tester (flow meter) (5) Load valve

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   Illustration 18	g02283194

6. Set the main pump pressure using load valve (5) on the flow meter. Use the arrows to adjust the flow. Refer to Table 2 for the load pressures and flow specifications.

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

Cat Electronic Technician Procedure

The following procedure will allow the user to calibrate the flow limit valves using the Cat Electronic Technician.

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Illustration 19	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 20	g02713758

2. Start Cat Electronic Technician.
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   Illustration 21	g02713761

3. Select the ECM for "Machine Control".
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   Illustration 22	g02723808

4. Select "Calibrations" from the "Service" menu.
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   Illustration 23	g02724846

5. Highlight "PRV - Main Pump Flow Limitation Pressure Calibration" and click on the "Start" button in the lower left corner of the screen.
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   Illustration 24	g02724848

6. Select the flow limit valves to calibrate and press the "Begin" button.
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   Illustration 25	g02724853

7. Follow the instructions on the screen. Press "Next" button to continue through to the next step.
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   Illustration 26	g02283033
   Portable hydraulic tester (flow meter) (5) Load valve

8. Set the main pump pressure using load valve (5) on the flow meter. Use the arrows to adjust the flow.

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

10. Set the main pump pressure using load valve (5) on the flow meter to 16000 ± 500 kPa (2321 ± 73 psi).

11. Use the arrows to adjust the flow until the flow reading for the flow limit valve is at 150 ± 2 L/min (39.6 ± 0.5 gpm). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

12. Repeat Steps 10 and 11 until the flow meter reads 150 ± 2 L/min (39.6 ± 0.5 gpm) and the pressure gauge reads 16000 ± 500 kPa (2321 ± 73 psi).

13. Press the "NEXT" button.

14. Set the main pump pressure using load valve (5) on the flow meter to 16000 ± 500 kPa (2321 ± 73 psi).

15. Use the arrows to adjust the flow until the flow reading for the flow limit valve is at 250 ± 2 L/min (66 ± 0.5 gpm). Press the device for activation 3 times and release the device for activation 3 times for each adjustment.

16. Repeat Steps 14 and 15 until the flow meter reads 250 ± 2 L/min (66 ± 0.5 gpm) and the pressure gauge reads 16000 ± 500 kPa (2321 ± 73 psi).

17. Press the "NEXT" button.

18. 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.

19. 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 and specifications. Refer to Table 2 for the load pressure and flow specifications.

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Illustration 27	g02726867

1. Select "Diagnostic Tests" from the "Diagnostics" menu.
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   Illustration 28	g02726886

2. Highlight "Main Pump Flow Limitation Pressure Test" and click on the "Start" button in the lower left corner of the screen.
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   Illustration 29	g02726938

3. Select the test and press the "Begin" button.
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   Illustration 30	g02726940

4. Follow the instructions on the screen. Press "Start" button in the lower left corner to begin the test.
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   Illustration 31	g02283033
   Portable hydraulic tester (flow meter) (5) Load valve

5. Set the main pump pressure using load valve (5) on the flow meter. Use the arrows to adjust the flow. Refer to Table 3 for the load pressures and flow specifications.