259D Compact Track Loader – Calibration

The calibration should be performed if the Machine ECM or any Machine component has been replaced or removed. The calibration menu is used to compensate for the differences in the mechanical components and the electrical components. The calibration should be performed if one of the following components has been replaced or removed. Perform all calibrations that are applicable. The calibrations are listed:

• Right Control Lever

• Left Control Lever

• Auxiliary Valve #1 Port B Solenoid

• Auxiliary Valve #1 Port A Solenoid

• Bucket Raise Solenoid

• Bucket Lower Solenoid

• Bucket Dump Solenoid

• Bucket Rackback Solenoid

• Forward Pump Solenoid Calibration

• Reverse Pump Solenoid Calibration

• Engine Cooling Fan Speed

• Accugrade Auxiliary Control Calibration

• Bucket Inclinometer Calibration - Self Level / Return to Dig

Note: If the Implement currents are adjusted or recalibrated, this action will affect the work tool self level performance. The machine will automatically display a diagnostic code asking for the self level system to be recalibrated. Even if you return the implement currents back to the original values, the self level system will have to be recalibrated. Make sure that all the implement currents are set to satisfaction FIRST. Then calibrate the work tool self level system, using the automatic procedure in Caterpillar Electronic Technician (Cat^® ET).

Implement Valve Current Calibration - Required Tools

• Laptop with Caterpillar Electronic Technician (Cat^® ET) installed

• Communications Adaptor

• Stopwatch

• Note Pad (worksheet) and Pen

Valve Break-in and Preparation for New Valve or Spool

1. Place machine in an area outside or near an exhaust snorkel on level ground.

2. Remove work tool, if equipped and set the parking brake.

3. Warm up and de-aerate the hydraulic system by continually cycling the lift/lower/rack/dump functions for 5 to 10 minutes. This action will help to break in the solenoids. Do not hold the function against the stops. This action causes oil to go from the valve back to tank so does not heat up the valve or break-in the solenoids.

4. Connect Communications Adaptor to machine and open up Cat^® ET.

Accessing Calibrations

Connect Cat^® ET to the machine. After communication has been established with Cat^® ET, click "Service" from the top menu and then "Calibrations" from the drop-own menu. The list of calibrations will appear. See Illustration 1

Read and understand the calibration warnings, see Illustration 2. Once the specific calibration is selected, Cat^® ET will list initial machine conditions that must be satisfied before the ECM will allow the calibration procedure to continue. Follow the on-screen instructions to calibrate the following functions:

• Lift

• Lower

• Dump

• Rack

Remember that the coupler and the arms need room to move in each direction so place both at MID STROKE position before you start. This action will allow for easier spotting of movement which is required as part of the calibration. Once the automatic calibration is completed, you will notice that the Minimum solenoid currents have been adjusted.

Open the Configuration screen in Cat^® ET. Click "Service" from the top menu and then "Configuration " from the drop-own menu or click the "Configuration Tool" icon (1) . Select the "Valve Calibration Currents" tab shown in Illustration 5.

Manual Adjustment of Minimum (Min) Current

After calibration, if the "start to move" or slow implement performance still needs to be fine-tuned, then use the previous values as a guide. The Lift / Lower / Dump / Rack Minimum Solenoid currents can be adjusted. During this adjustment, always set the engine to Max speed. Engine speed has a significant effect on hydraulic performance.

Note: The automatic implement solenoid calibration can always be repeated to restore factory performance. Or write the original values back into Cat^® ET.

To make the implement start to move with less joystick motion, increase the Min current in 0.01 Amp steps. Test the change by moving the joystick a tiny amount and monitor the implement movement. Monitor how much joystick movement was given after each adjustment.

To make the implement start smoother, or with more control, decrease the Min current in 0.01 Amp steps. Test the change by moving the joystick a small amount and then monitor the implement movement. If the implements started with a bump, this situation should start to disappear

Full Flow or Maximum (Max) Current Calibration

The full flow calibration sets the implement valve current for when the joystick is fully stroked. This process is NOT automated in Cat^® ET like the Initiation / Minimum current calibration. The Technician has to adjust the current going to the solenoid valve manually using Cat^® ET, then record the cycle time of the function. The objective is to reach the quickest cycle time with the lowest amount of current. This process gives the smoothest response of the joystick while still achieving Max cylinder speed.

If the automatic Cat^® ET procedure was used to calibrate Min currents, then the values have been updated for Lift, Lower, Dump, and Rack. For a cross reference to identify the correct functions in Cat^® ET, refer to Table 1.

Full Flow Current Calibration Directions

1. Refer to the above "Valve Break-in and Preparation for New Valve or Spool", if not yet carried out.

2. Open the Configuration screen in Cat^® ET. Click "Service" from the top menu and then "Configuration " from the drop-own menu or click the "Configuration Tool" icon (1) . Select the "Valve Calibration Currents" tab shown in Illustration 5.

3. Lift snubbing must be disabled prior to calibrating the full flow (maximum) currents. Check if the machine is equipped with the lift snubbing and whether the option is enabled. Lift snubbing is disabled in Cat^® ET on the configuration screen, under Implement Configuration. Make sure to return the snubbing option back to the original state after the implement calibration is complete.

Illustration 6	g03699299
Edit Solenoid Current Values




Illustration 7	g03699312
Enter New Solenoid Current Value and Confirm

4. Start with Lift by entering 0.900 Amp into the "Loader Lift Cylinder Extend Solenoid Current". Simply select that line by double clicking the amperage value and writing in the new current value (0.900 Amp) in the "Change Value Parameter" box. Then click "OK" and "Yes" to confirm the parameter change. Refer to Illustration 6 and Illustration 7.

5. Set the Park Brake.

6. Record the current on a calibration worksheet. See Illustration 9.

7. Fully Lower the Lift arms to the Stops.

8. Set the Engine RPM to Maximum

9. Apply a full raise command to the joystick and start the stop watch simultaneously. When the lift arms reach the upper stops, stop the stopwatch and write down that cycle time on the calibration worksheet.

   For implement cycle time specifications, refer to Testing and Adjusting , UENR3729, "Operational Checks".

10. Now increase the Lift current by 0.025 Amps to 0.925 Amps. After entering the new current value in the "Change Value Parameter" box, click "OK" and "Yes" to change the parameter.

11. Repeat Steps 6 through 9. You may have noticed an increase in cylinder speed due to the higher current. Retest the cycle time after each current change. Write down the cycle time and valve current each time on the calibration worksheet.

You will get to a point where the cylinder function will not get any faster even though you have added more current. Re-enter the lowest current that still gave the maximum cycle cylinder speed (shortest cycle time recorded). This value is the Max Solenoid Current for that function.

Note: If the cylinder cycle time is only decreasing slightly after increasing the current significantly, then this minor change should be ignored. Select the current that gave the highest cylinder speed (decrease in cycle time) that showed a significant improvement on the next lower current.
The objective is to reach the quickest cycle time with the lowest amount of current.
Adding more current than required will make the joy stick jerky, especially on raise and lower. Be careful not to make the current too high.

Lower Calibration

The Lower Calibration should be set to the lowest current that gives the cycle time provided in the calibration worksheet. The cycle time should not necessarily be set to the maximum speed. If Lower Calibration is set too fast, there may be problems with Self Level and Return to Dig performance. Too much Max current can cause the lift arm to activate 'float down' mode when trying to power down.

For implement cycle time specifications, refer to Testing and Adjusting , UENR3729, "Operational Checks".

The calibration current will vary across implement functions and from machine to machine. Refer to Illustration 8 for an example of typical calibration notes.

Once Lift is completed, repeat the procedure for the other functions, Lower, Dump, and Rack. Remember the objective is to reach the fastest cycle time with the lowest amount of current. Adding more current than required will make the joystick jerky to operate and will not give and more implement speed.

If lift snubbing was disabled, then enable the lift snubbing function when calibrations are finished.

Note: For flow rate specifications for the work tool pump, refer to Testing and Adjusting , UENR3729, "Pump Flow - Test".