VALVE GP-BANK 4 2096764 - Caterpillar

Standard Tooling
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Table 2 provides a list of the required tools if standard tooling is used to perform the following test procedure.
Table 2
Required Tools (Standard Tooling)    
Tool    Item    Part Number    Description    Qty    
B     B1     177-7860     Hose     1    
B2 6V-4143     Coupler     2    
C     -     4C-6500     Digital Thermometer     1    
D     D1     177-7861     Hose     2    
6V-4143 Coupler 4    
D2 6V-3989     Fitting     2    
8T-0860 Pressure Gauge
0 - 40000 kPa (0 - 5800 psi)     2    
To avoid damage to the vibratory system during testing, always perform the testing with the vibratory drum on top of tires or on loose dirt. Tires will simulate a non-compacted soil condition.Never operate the vibratory system when the machine is on concrete.
If a testing time longer than three (3) minutes is required, rotate the drum periodically in order to lubricate the eccentric weight shaft bearings.
Test Procedure
The 198-4240 Digital Pressure Indicator and several of the Standard tools are used in the following test.
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Vibratory Pump (X1) Servo port (X2) Servo port
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Vibratory Pump (1) Servo (2) Locknut (3) Servo valve neutral adjustment screw
Make sure that the parking brake is applied. Make sure that the propel control lever is in the NEUTRAL position.
Disconnect the electrical connection for the vibratory pump control.
Install Tool (B) between port (X1) and port (X2). Tool (B) is used as a jumper hose.
Install a Tool (A2) to each location of the main relief valve test ports.
Start the engine and run the engine at high idle at 2310 45 RPM. Check the hydraulic temperature with Tool (C) until the hydraulic oil temperature is at a minimum of 38°C (100°F).
Read the pressure readings on Tool (A1) for each relief valve. The pressure readings should be identical.Adjusting Procedure
If the pressure readings are not identical, loosen locknut (2) so that the neutral position of the servo piston may be adjusted. Use an allen wrench in order to turn servo valve neutral adjustment screw (3). Turn the screw clockwise or counterclockwise in order to adjust the mechanical center of the servo valve. The pressures on each Tool (A2) should change. Turn servo valve neutral adjustment screw (3) until the pressure readings on each Tool (A2) are equal. Tighten locknut (2) .
Stop the engine. Remove Tool (A2) from each relief valve test port.
Remove Tool (B) .
Connect the electrical connection for the vibratory pump control.