LINES GP-AIR COMPRESSOR 3534681 - Caterpillar

Blade Line Relief Valve
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 1 g02845957
Pump compartment (1) Pressure tap (delivery pressure)
Connect a 60000.0 kPa (8700.0 psi) pressure gauge to pressure tap (1) .
Start the engine.
Place the machine controls at the following settings: Engine speed at high idle, and AEC switch OFF. Refer to Testing and Adjusting, "Engine Performance - Test (Engine Speed)" for engine rpm settings.
Place the hydraulic activation control lever in the UNLOCKED position.
Increase the hydraulic oil temperature to 55° 5°C (131° 9°F).
Illustration 2 g02846096
Main control valve (2) Line relief valve (head end of blade cylinder)
Illustration 3 g01459839
Line relief valve (4) Locknut (5) Adjustment screw
To adjust line relief valve (2) for the head end of the blade cylinder, move the blade control lever to the full LOWER position (full retraction of the blade cylinder). Hold the blade control lever in this position.
Check the line relief valve pressure setting of the blade cylinder at pressure tap (1) .
Return the blade control lever to the NEUTRAL position.
Loosen locknut (4) on blade line relief valve (2). Turn adjustment screw (5) until the pressure gauge reading at pressure tap (1) is 28000.0 - 30000.0 kPa (4061.0 - 4351.0 psi).Note: Turning adjustment screw (5) clockwise increases the pressure. Turning adjustment screw (5) counterclockwise decreases the pressure.Note: Always make final pressure adjustment on pressure rise.
Tighten locknut (4) to a torque of29 2 N m (21.0 1.0 lb ft.)