GEAR-DRIVE 1694778 - Caterpillar

Specification
Table 1
"Relief Valve (Main) - Test and Adjust"    
Date     Machine Serial Number    
Machine Settings     Engine Speed    
Speed Dial "10"
AEC switch OFF
Item     Specification     Actual    
Main Relief     35000 + 500 - 1000 kPa (5076 + 73 - 145 psi)        Required Tools
Illustration 1 g02571852
Tooling (A) 198-4240 Digital Pressure Indicator Gp
Table 2
Tool    Item    Qty    Part Number    Description    
A         198-4240     Digital Pressure Indicator Gp    
    A1     1     198-4234     Indicator    
A2 1     198-4239     Pressure Sensor
41,368 kPa (6,000 psi)    
A3 1     198-4236     Extension Cable    Machine Preparation
Position the machine on level ground and stop the engine.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".
Illustration 2 g01217778
Pump compartment (1) Pressure tap (delivery pressure for drive pump) (2) Pressure tap (delivery pressure for idler pump) (3) Pressure tap (power shift pressure)
Attach a 41,368 kPa (6,000 psi) pressure sensor to pressure tap (1) .Test Procedure
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).
Open the bucket until the bucket cylinder rod is at the full retraction.
Check the main relief valve pressure setting at pressure tap (1) .
Return the joystick for the bucket to the NEUTRAL position.
The main relief valve pressure setting should be 35000 + 500 - 1000 kPa (5076 + 73 - 145 psi). If the main relief valve pressure setting is not within the specification, adjust the main relief valve pressure setting.Adjustment Procedure
Illustration 3 g00666196
(4) Adjustment screw (5) Locknut (6) Main relief valve
In order to adjust the main relief valve, loosen locknut (5) and turn adjustment screw (4) until the pressure gauge reading at pressure tap (1) is 35000 + 500 - 1000 kPa (5076 + 73 - 145 psi).Note: Turning adjustment screw (4) clockwise increases the pressure. Turning adjustment screw (4) counterclockwise decreases the pressure.Note: Always make final pressure adjustments on pressure rise.
Tighten locknut (5) to a torque of 50 10 N m (37 7 lb ft).
Temporary Setting of the Main Relief Valve
Note: A temporary setting of the main relief valve is required before any line relief valve can be adjusted.
The main relief valve pressure setting should be 35000 + 500 - 1000 kPa (5076 + 73 - 145 psi). If the main relief valve is not within the specification, adjust the main relief valve pressure setting to the correct pressure specification before performing Step 2. Refer to Testing and Adjusting, "Relief Valve (Main) - Test and Adjust".
Illustration 4 g00666196
Top of main control valve (4) Adjustment screw (5) Locknut (6) Main relief valve
Loosen locknut (5) and turn adjustment screw (4) clockwise for one half turn. Tighten locknut (5) to the specified torque.Note: Always make final pressure adjustments on pressure rise.