- "Control Lever"
- "Throttle Position"
- "Raise Solenoid #1"
- "Lower Solenoid #1"
- "Rackback Solenoid #1"
- "Auxiliary Hydraulics Lever"
- "Left Drive Pump Forward Control Solenoid"
- "Left Drive Pump Reverse Control Solenoid"
- "Right Drive Pump Forward Control Solenoid"
- "Right Drive Pump Reverse Control Solenoid"
- "Auxiliary Valve #1 Solenoid #1"
- "Auxiliary Valve #1 Solenoid #2"
- "Right Joystick Forward/Reverse Position Sensor"
- "Left Joystick Left/Right Position Sensor"
- "Right Joystick Left/Right Position Sensor"
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
- Place machine in an area outside or near an exhaust snorkel on level ground.
- Remove work tool, if equipped and set the parking brake.
- 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.
- 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 2
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| Illustration 1 | g03700375 |
Calibration Menu in Cat® ET | |
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| Illustration 2 | g03699282 |
Calibration Warning | |
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| Illustration 3 | g03704995 |
Selection Screen for Bucket Solenoid Calibration | |
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| Illustration 4 | g03705023 |
Set-Up Conditions for Bucket Solenoid Calibration | |
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.
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| Illustration 5 | g03705037 |
Configuration for Valve Calibration Currents (1) "Configuration Tool" icon | |
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.
| Cross Reference to Identify Correct Functions in Cat® ET | |
|---|---|
| Loader Lift Cylinder Extend | Lift |
| Loader Lift Cylinder Retract | Lower |
| Bucket Cylinder Extend | Dump |
| Bucket Cylinder Retract | Rack Back |
Full Flow Current Calibration Directions
- Refer to the above "Valve Break-in and Preparation for New Valve or Spool", if not yet carried out.
- 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 6.
- 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.
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| Illustration 6 | g03699299 |
Edit Solenoid Current Values | |
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| Illustration 7 | g03699312 |
Enter New Solenoid Current Value and Confirm | |
- Set the Park Brake.
- Record the current on a calibration worksheet. See Illustration 1.
- Fully Lower the Lift arms to the Stops.
- Set the Engine RPM to Maximum
- 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.
Reference For implement cycle time specifications, refer to the following:
Testing and Adjusting , KENR5113, "Operational Checks" for 246C, 256C, 262C, 262C2, and 272C.
Testing and Adjusting , KENR8830, "Operational Checks" for 279C, 279C2, 289C, 289C2, and 299C.
- 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.
- Repeat Steps 5 through 8. 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.
- Repeat this "Full Flow Current Calibration" process for the other three functions listed in Table 1.
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 , KENR5113, "Operational Checks".
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| Illustration 8 | g03699304 |
Typical Calibration Notes (arrow points to best current selection.) | |
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.
Note: For flow rate specifications for the work tool pump, refer to Testing and Adjusting , KENR5113, "Pump Flow - Test".
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| Illustration 9 | g03700181 |
| Full Speed Time Specifications (1) | ||||
| Model and Valve Type | Raise Loader Lift Cyl Extend |
Lower Loader Lift Cyl Retract |
Dump Bucket Cyl Extend |
Rack Bucket Cyl Retract |
| 246C/ 256C/ 277C/ 279C "Standard Aux" |
3.1 sec | 2.8 sec | 2.5 sec | 2.1 sec |
| 262C/ 272C/ 287C/ 289C/ 297C/ 299C "Standard Aux" |
4.7 sec | 3.7 sec | 2.5 sec | 2.1 sec |
| 246C/ 256C/ 277C/ 279C "XPS High Flow" |
3.1 sec | 2.8 sec | 2.5 sec | 2.1 sec |
| 262C/ 272C/ 287C/ 289C/ 297C/ 299C "XPS High Flow" |
4.5 sec | 3.6 sec | 2.5 sec | 2.1 sec |
| ( 1 ) | Cycle time tolerance for all functions is ± 0.5 seconds |