CYLINDER GP-HYDRAULIC 3967143 - Caterpillar

Left and Right Valve Calibrations
The valve calibrations are automatic sequences that the Grade Control system performs to tune the tow point valve to the system. The Grade Control system applies electrical current to the tow point valve in order to determine the operating range of the valve. The operating range of the valve is crucial in order to have a properly performing Grade Control system. Caterpillar recommends performing the calibration procedure periodically for optimum system performance.Note: The left and right valve calibration procedures are identical. Left calibration applies to the left tow point valve and right valve calibration applies to the right tow point valve. Repeat procedure for opposite side.Note: Calibration can only be performed on one side at a time. Once a calibration has been started on a display, do not interact with Grade and Slope screens on other displays.The following components are required in order to perform a valve calibration:
ST200 sonic sensor
Sensor coil cord
Necessary brackets to ensure that the ST200 is positioned even with the tow point cylinder
Park the machine on a flat and a level surface.
Center the tow point cylinder to the middle of the cylinder stroke, using the controls on each side of the machine.
Lower the screed. Drive the machine forward a few inches in order to remove any slack from the tow arms.
Neutralize the pitch of the screed using the thickness control screw on each side of the machine. When pitch of the screed is neutralized, little or no resistance is felt when turning the thickness control screw.Note: On machines with no thickness control screws, use the tow point jog switches to align the screed so that the main plate is flat on the ground.
Position a sonic tracer directly next to the tow arm cylinder on the side to be calibrated.Note: The sonic tracer must be oriented for use over a surface that is parallel to the side of the machine and approximately 46 cm (18 inch) above the surface.
Select sonic sensor on main screen.Note: You cannot perform a valve calibration with a contact or slope sensor.
Bench the sonic sensor on the main screen.
Select "Installation" from the main menu screen. Follow the preparation steps in order on the screen:
Select "Left or Right Valve Calibration" from the Installation menu.
Warm oil.Note: Warm the machine oil to at least 45° C (113° F). Operate the paver augers and conveyors at full throttle to help warm the hydraulic oil. Cycle the tow point cylinder up and down several times so that warm oil enters the valve and cylinder.
Ensure that the machine is configured to allow the system to control the tow points.
Engine running (low idle)
Propel mode set to "Pave"
Parking brake engaged
Propel lever forward
Screed in float
Ensure that sonic sensor is properly positioned, as per Step 5.
Touch "Completed – continue to calibration" or button next to right facing arrow.
Illustration 27 g06204616
"Set normal take off position" and press "OK" softkey when tow arm is centered.Note: Normal take off position, is the starting point of tow point cylinder centered with the