PANEL AS 4645031 - Caterpillar

Specification
Note: Certain machines will default to "Economy Mode" at machine startup. Change to "High Hydraulic Power Mode" before performing the test procedure.
Table 1
"Relief Valve (Pilot) - Test and Adjust"
Machine Settings Engine Speed
Speed Dial "10"
AEC switch OFF
Item Specification Actual
Pilot relief valve pressure 4100 200 kPa (595 29 psi) Introduction
The pilot relief valve is located on the mounting base for the pilot oil filter. The pilot relief valve limits the pressure in the pilot system. The pilot relief valve setting is adjustable.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 Digital Pressure Indicator
A2 1 198-4238 Pressure Sensor 34,450 kPa (5,000 psi)
A3 1 198-4236 Adapter Cable As Machine Preparation
Position the machine on level ground.
Stop the engine.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "Hydraulic System Pressure - Release".
Illustration 2 g01631853
Pilot relief valve (located in pump compartment)
(1) Locknut
(2) Adjustment screw
(3) Pressure tap
(4) Pilot filter
Connect a 34,450 kPa (5,000 psi) pressure sensor to pressure tap (3). 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).
Check the pilot relief valve setting at pressure tap (3).
The pilot relief valve setting should be 4100 200 kPa (595 29 psi). If the pilot relief valve setting is not within the specification, then adjust the pilot relief valve. Adjustment Procedure
In order to adjust the pilot relief valve, loosen locknut (1).
Turn adjustment screw (2) until the pressure reading at pressure tap (3) is within the specification. Note: Turn adjustment screw (2) clockwise in order to increase the pressure. Turn adjustment screw (2) counterclockwise in order to decrease the pressure.Note: Always make final pressure adjustments on pressure rise.
Tighten locknut (1) to a torque of 49 5 N m (36 4 lb ft).
Test the pressure setting again. Refer to "Test Procedure". Note: Normal operation of the engine and pumps are necessary for the pressure adjustment. If the results of the pressure adjustments are not correct, then check the engine and the pump characteristic curve.