WIRE 1376132 - Caterpillar

Specification
Table 1
"Relief Valve (Pilot) - Test and Adjust"
Item Machine Settings Specification Actual
Engine Speed
Pilot Relief Valve Speed Dial "10"
AEC switch OFF 4100 200 kPa (595 29 psi)
Illustration 1 g02593337
Table 2
Torque Specification
Item Part Torque
1 Pilot Relief Valve 118 10 N m (87 7 lb ft)
2 Locknut 49 5 N m (36 4 lb ft) Introduction
The pilot relief valve is 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 2 g02571852
Tooling (A) 198-4240 Digital Pressure Indicator Gp
Table 3
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 Test Preparation
Place the machine on level ground.
Stop the engine.
Release the pressure in the hydraulic system. Refer to Testing and Adjusting, "System Pressure - Release".
Illustration 3 g02973840
Pilot Filter (located in pump compartment)
(1) Pilot relief valve
(2) Locknut
(3) Adjustment screw
(4) Pressure tap
(5) Pilot filter
Connect a 34,450 kPa (5,000 psi) pressure sensor to pressure tap (4).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 (4).
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
To adjust the pilot relief valve, loosen locknut (2).
Turn adjustment screw (3) until the pressure reading at pressure tap (4) is within the specification.Note: Turn adjustment screw (3) clockwise to increase the pressure. Turn adjustment screw (3) counterclockwise to decrease the pressure.Note: Always make final pressure adjustments on pressure rise.
Tighten locknut (2) to a torque of 49 5 N m (36 4 lb ft).
Test the pressure setting again. Refer to "Specification".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.