BEARING 7D7851 - Caterpillar

Introduction
This testing procedure will allow the technician to evaluate the pressure setting of the charge oil for the front and rear hydrostatic pumps.Required Tools
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Tooling (A) 198-4240 Digital Pressure Indicator Gp
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Tooling (B)
466-6259 Communication Adapter Gp
Table 2
REQUIRED TOOLS
Tool Item Qty Part Number Description
A 1 198-4240 Digital Pressure Indicator Gp
A1 1 198-4234 Digital Indicator
A2 1 198-4239 Pressure Sensor Gp
(0 kPa to 41,368 kPa (0 psi to 6,000 psi))
A3 1 198-4236 Adapter Cable As
1 Laptop computer with Cat® Electronic Technician (Cat ET) Service Tool
B 1 466-6258(1) Communication Adapter Gp
B1 1 370-4617 Cable As
B2 1 317-7485 Communication Adapter
B3 1 327-8981 Cable As
457-6114 Cable As
(1) Cat ET and Software CD, NETG5057 are required when using the communication adapter.Reference: Refer to Tool Operating Manual, NEHS0818, "Using the 198-4240 Digital Pressure Indicator Group" for more information on using Tooling (A).Test Preparation - Charge Relief Valve
Move the machine to a smooth horizontal location.
Permit only one operator on the machine. Keep all other personnel away from the machine or in the operator sight.
Place the steering control lever in the NEUTRAL position.
Engage the parking brake.
Lower the attachments to the ground.
Stop the engine.
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Remove cover (2).
Connect Tooling (B) to service tool connector (E1).
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Connect Tooling (A) to pressure taps (P5).Note: The hydraulic oil filters are located behind the access panel on the left-hand side of the machine.Test Procedures - Charge Relief Valve
Start the engine and run the engine at HIGH IDLE.
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Record the charge pressure in the specification table the "Specifications" section.Note: The charge pressure should be equal to the lower pressure for each of the drive pumps.
The engine speed should be 2100 100 rpm.
The charge pressure at pressure tap (P5) for the left drive pump should be 2800 150 kPa (406 22 psi).
Decrease engine speed to LOW IDLE.
Stop the engine.
If the charge pressure is not within specifications, adjust the charge relief valve for that circuit and perform the initial test again.Adjustment Procedures - Charge Relief Valve
Note: The following procedure allows the operator guidelines needed for increasing or decreasing pressure for the charge relief valve.
If the engine is still running, stop the engine.
Exit the machine.
Remove the floor panel in the cab.
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Relief valve (1) is not adjustable and must be replaced if the charge relief pressure is out of specification.