Adjustment of the Hydraulic Electronic Controls{5702} Caterpillar

Wheel Tractors:

824G (PIN: 4SN1-UP)

Soil Compactors:

825G (PIN: 6RN1-UP)

Landfill Compactors:

826G (PIN: 7LN1-UP)

Introduction

This Special Instruction is necessary for adjusting the 153-8465 Hydraulic Electronic Control , the 164-1943 Hydraulic Electronic Control , and the 164-1944 Hydraulic Electronic Control .

Do not perform any procedure that is outlined in this publication or do not order parts until you understand the information that is contained in this document.

Troubleshooting Procedure to Mechanically Adjust the Hydraulic Electronic Controls

The following troubleshooting can be used to identify probable causes of calibration problems. The following procedure assumes all hydraulic parts and all electronic parts are operating properly.

The top cover and the bottom cover must be removed in order to adjust the hydraulic electronic control lever. Use the following procedure to remove the covers.

Procedure to Remove the Covers from the Hydraulic Electronic Control

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Illustration 1	g00563093

1. Remove knob (1) .

2. Remove nut (2) in order to remove spacers (3) and covers (4) .

3. Remove bottom plate (6) by removing three screws.

4. Remove electrical connectors and wiring harnesses (7) .

5. Remove cover (5) by removing two screws.

Slow Movement of the Blade at the Lower Position

Probable Cause: Adjustment of the detent rod is required.

Corrective Action:

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Illustration 2	g00543442

1. Loosen locknut (1) at the spherical rod end.

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Illustration 3	g00568273
View A

2. Hold the control lever in the LOWER position. Turn detent rod (2) clockwise (A) until the blade goes into Float mode and drops.

3. Turn detent rod (2) counterclockwise (B) into the rod end half a turn until the Float mode does not occur at the maximum LOWER position. Tighten locknut (1). Ensure that the Float mode is not at the maximum LOWER position.

4. If the attachment still drops, repeat Step 3. At this setting the blade will have maximum power down velocity.

Blade Drops When the Control Lever is at the Maximum LOWER Position or Prior

Probable Cause: Adjustment of the detent rod is required.

Corrective Action:

1. Loosen locknut (1) at the spherical rod end.

2. Turn detent rod (2) counterclockwise (B) as many times as required until the problem is corrected.

Blade Does Not Go Into Float Mode When the Control Lever is in Float Detent

Probable Cause: Adjustment of the detent rod is required.

Corrective Action:

1. Loosen locknut (1) at the spherical rod end.

2. Turn detent rod (2) clockwise (A) until the system goes into the Float mode. Ensure the control lever is at the maximum LOWER position.

3. Turn detent rod (2) counterclockwise (B) into the rod end half a turn until the Float mode is not at the maximum LOWER position.

Control Lever has Excessive Play in the Tilt Direction When in the Hold Position

Probable Cause: Adjustment of the screws are required.

Corrective Action:

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Illustration 4	g00543536

1. Loosen two locknuts (3) and adjust two screws (2) in a counterclockwise direction. Turn screws (2) until the screws contact lever (1) on either side. There should be no clearance between the top of the adjusting screws and the contact surfaces of the lever. The lever should not have any movement unless springs (4) are stretching.

2. Ensure that control lever (1) is as vertical as possible. Lock the adjusting screws in place.

   Note: The vertical position of the control lever can be set with electronic instruments. Set the duty cycle at 50% ± 1% in order to position the control lever at vertical.

Control Lever Has Excessive Play Around the Hold Position in the Lift Direction

Probable Cause: Adjustment of the screws are required.

Corrective Action:

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Illustration 5	g00543541

1. Loosen locknuts (1) on both adjustment screws (2). The adjustment screws can be accessed from the right side of the control module. A gap will be present between the head of the screw and the lever on either side.

2. Drive the adjusting screws toward the lever equally on both sides. This will eliminate the gap between the levers and the heads of the adjusting screw. Ensure that the control lever is vertical in the HOLD position.

   Note: The gap is eliminated as the adjusting screws are driven closer to the contact surfaces of the levers. The gap will appear again if the screws are driven too far. This time the gap is formed between the adjusting lever and the housing shaft.

Electronically Adjusting the Hydraulic Electronic Controls Using CAT ET ( Caterpillar Electronic Technician)

1. Park the machine on a smooth, level surface. Move away from other operating machines and away from personnel. Lower the blade to the ground. Stop the engine.

2. Permit only one operator on the machine. Keep other personnel away from the machine or in the operator's sight.

3. Engage the parking brake. Place blocks in front of the wheels and behind the wheels.

   Note: Do not stop the machine with the front of the machine off the ground unless this is required for the test. Lower the machine to the ground and stop the engine.

4. Turn the engine start switch to the ON position. However, do NOT start the engine. Place the implement lockout switch in the ON position.

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Illustration 6	g00280782
Connections for the Electronic Technician (ET) The following components are needed to use CAT ET to determine service codes. (1) IBM compatible personal computer with Caterpillar Electronic Technician software installed. (2) 139-4166 Data Link Cable or 7X-1570 Data Link Cable . (3) 7X-1425 Cable and 4C-6805 Adapter . (4) NEXG4523 Caterpillar Electronic Technician software. (5) 7X-1700 Communication Adapter Tool .

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Illustration 7	g00540804
(6) Diagnostic service tool connector (ET). (7) Machine harness code connector. (8) Service connector (switch box).

5. Install CAT ET. Electronic Technician connects to the machine service connector and communicates with the ECM over the data link. The service connector is located behind the fuse panel access cover in the right interior panel of the cab. For more information and the locations of the connectors, see Testing and Adjusting, "Electrical Components and Connector Locations" and the Electrical System Schematic in your machine's Service Manual.

   Electronic Technician is not needed to determine or clear service codes. Electronic Technician can display information on service code history and parameter status.

   Note: Electronic Technician is a software program that can be used on an IBM compatible personal computer.

   Reference: To use Electronic Technician, order Special Publication, JERD2124, "ET Single Use Program License", Special Publication, JEHP1026, "Information and Requirements Sheet", and Special Publication, JERD2142, "Data Subscription". Special Publication, JEHP1026, "Information and Requirements Sheet" lists the required hardware and features of Electronic Technician.

6. Start the Electronic Technician after the communications adapter and the computer have been connected to the machine. The Electronic Technician will initiate communications with the ECMs on the machine. After communication has been established, the Electronic Technician will list the ECMs on the machine.

   Adjustments to the control lever can be made by using the Electronic Technician and measuring the duty cycle of the lever sensors. All versions of the Electronic Technician and all combinations of implement software can view the duty cycle of the lever sensors.

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Illustration 8	g00545432
Electronic Technician 825G Implement Control Opening Screen

7. The next menu is a list of the Electronic Control Modules ECMs installed on the machine. Choose the Implement Control ECM for information on this control.

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Illustration 9	g00545439
Electronic Technician 825G Implement Control Group Screen

8. Select Implement Control Group 1.

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Illustration 10	g00567976

9. Loosen locknut (1) at the spherical rod end.

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Illustration 11	g00545468
Electronic Technician 825G Implement Control Group 1 Screen

10. This screen contains the duty cycle information for the lift sensor. Verify that the lever is centered. Record the percent duty cycle of the lift position sensor.

    Note: The percent duty cycle for the lift position sensor must be between 46% and 54%. If the sensor reading is outside this reading, follow adjustment procedure ""Control Lever has Excessive Play in the Tilt Direction When at the Hold Position" " or ""Control Lever Has Excessive Play Around the Hold position in the Lift Direction" ".

    Note: The duty cycle measurement may be slightly different between the Electronic Technician and a digital multimeter. Use the same tool throughout the entire procedure.

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Illustration 12	g00545474
Electronic Technician 825G Implement Control Group 1 Screen

11. Subtract 21% from the reading taken in Step 11. For example, if the recorded center position was 47%, then 47% minus 21% equals 26%. This will be the sensor reading when the lever is at the maximum LOWER position.

12. Push the lever forward until the detent is felt.

13. Adjust the lift detent until the reading of the lift lever sensor is at the value calculated from Step 11.

14. Release the lever to the center position and tighten the locking nut on the detent adjustment.

15. Move the lever forward and verify that the start of detent is still at the calculated value from Step 11. If detent has shifted, repeat Steps 13 through 14.

16. Ensure that the lever is centered. Turn the keyswitch OFF, then turn the keyswitch ON. Do NOT start the engine.

17. Place the implement lockout switch in the OFF position.

18. If the blade is not resting on the ground, slowly lower the blade by moving the lever forward.

19. View ET Status Screen 1. Observe the current of Lower Solenoid 1.

20. Move the lever to the maximum LOWER position while the blade is resting on the ground. The lower current should increase to the maximum modulation current of 55% to 75%. At no time should the current increase to 100 percent. A current of 100% indicates FLOAT. If the current reads 100% at the start of detent, repeat Steps 8 through 15.

21. Slowly move the lever into the detent position. Approximately halfway through the detent position, the current of the lower solenoid should increase to 100%.

22. Allow the mechanical stop to hold the lever in the detent position. The lower current should remain at 100%. If the current drops to the maximum modulation current of 55% to 75%, repeat Steps 8 through 15.

23. Move the joystick to the HOLD position and turn the keyswitch OFF.

Adjusting the Hydraulic Electronic Controls Using a Digital Multimeter

Ensure that the key switch is in the OFF position. Make the following connections to the harness that is connected to the lift lever position sensor. DO NOT disconnect the machine harness from the lift lever position sensor.

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Illustration 13	g00386923
Position Sensor (Lift Lever) Schematic

1. Connect the red lead (voltage) from the multimeter to wire 146-GY. Inserting the probe into the rear of the 3 pin connector.

2. Connect the black lead (common) from the multimeter to wire 299-BK. Insert the probe into the rear of the 3 pin connector.

3. Turn the engine start switch to the ON position. However, do NOT start the engine. Place the implement lockout switch in the ON position.

4. Place the selector switch on the multimeter to "AC Voltage".

5. Press the frequency ("Hz") button on the multimeter twice. This selects the duty cycle ("%") mode.

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Illustration 14	g00567976

6. Loosen locknut (1) at the spherical rod end.

7. Verify that the lever is centered. Record the percent duty cycle of the lift position sensor.

   Note: The percent duty cycle for the lift position sensor must be between 46% and 54%. The duty cycle measurements may be slightly different when choosing between ET and a digital multimeter as a tool to measure duty cycle. Use the same tool throughout the entire procedure.

8. Subtract 21% from the reading taken in Step 7. For example, if the recorded center position was 50%, then 50% minus 21% equals 29%. This will be the start of the detent position.

9. Push the lever forward until the detent is felt.

10. Adjust the detent until the multimeter reading is at the value calculated from Step 8.

11. Release the lever to the center position and tighten the locking nut on the detent adjustment.

12. Move the lever forward and verify that the start of detent is still at the calculated value from Step 8. If detent has shifted, repeat Steps 10 11.

13. Turn the engine start switch to the OFF position. Then turn the engine start switch to the ON position. Start the engine. Place the implement lockout switch in the ON position.

    Note: This allows the ECM to recalibrate for the new center position.

14. Move the blade with the control lever. When the control lever is moved forward to the maximum LOWER position, the implements should be at full power down. If the FLOAT is active, repeat the adjustment procedure.

15. Slowly lower the blade to the ground. Move the lever forward into detent and allow the mechanical detent to hold the lever into position. FLOAT should be active. If the front of the machine is raised off the ground, slowly lower the machine to the ground and repeat the adjustment procedure.