330F MHPU Mobile Hydraulic Power Unit Machine System Caterpillar

Solenoid Valve (Proportional Reducing) - Calibrate - Power Shift Pressure

Usage:

330F B32

Introduction

The proportional reducing valve for the power shift pressure is located on the main pump housing. The proportional reducing valve sends the reduced pilot oil pressure to the regulators at the idler pump and the drive pump. The output flow of the idler pump and the drive pump is controlled in accordance with the power shift pressure. Power shift pressure is controlled by the machine ECM.

Required Tools

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Illustration 1	g02571852
Tooling group "A" 198-4240 Digital Pressure Indicator Gp

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Table 1
Tool	Item	Qty	Part Number	Description
A			198-4240	Digital Pressure Indicator Gp
	A1	1	198-4234	Indicator
	A2	1	198-4237	Pressure Sensor 3447 kPa (500 psi)
	A3	1	198-4236	Extension Cable

Machine Preparation

The following procedure 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.
Position the machine on level ground.
Stop the engine.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
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Illustration 2 g03687817

Pressure tap for the proportional reducing valve (power shift pressure)
Connect a 3447 kPa (500 psi) pressure sensor to the pressure tap for power shift pressure.
Start the engine.
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.
Increase the hydraulic oil temperature to 55° ± 5°C (131° ± 9°F).

Calibration Procedure

Enter the service mode. Input the password "9992".
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Illustration 3 g02306455
Select "Power Shift Pressure" from the "Calibrations" menu.
Press the OK key in order to start the calibration. The engine RPM will automatically increase to the equivalence of engine speed dial 10.
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 4 g02542459
Use the arrows to adjust the pressure until the pressure reading for power shift pressure is at 500 ± 50 kPa (73 ± 7 psi). Press the OK key.
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Illustration 5 g02542476
Use the arrows to adjust the pressure until the pressure reading for power shift pressure is at 2500 ± 50 kPa (363 ± 7 psi). Press the OK key.
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Illustration 6 g02542496
If calibration was successful and no errors occurred, the display will indicate that the calibration is complete.
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Illustration 7 g02542497
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.