TREAD 1289721 - Caterpillar

Adjustment Procedures
Table 2
Required Tools    
Part Number     Description     Qty    
6V-2100     Multitach group     1    
6V-4161     Hydraulic testing group     1    
8T-0470     Thermometer group     1    
Table 3
Relief Valves    Pressure change With One Turn Of Adjustment Screw    
Main valves    
14400 kPa (2100 psi)    
Line relief valve    
11000 kPa (1600 psi)    
Swing relief valve    
11200 kPa (1625 psi)    
Travel crossover relief valve    
3050 kPa (440 psi)    
Pilot relief valve    
690 kPa (100 psi)    Preparation For Relief Valve Adjustment
Illustration 2 g00542589
Pump compartment (1) Pressure tap (power shift pressure) (2) Pressure tap (front pump delivery pressure) (3) Pressure tap (rear pump delivery pressure)
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".
Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (2). Connect a 60000 kPa (8700 psi) pressure gauge to pressure tap (3) .
Connect a 4000 kPa (580 psi) pressure gauge to pressure tap (1) .
Start the engine.
Increase the hydraulic oil temperature to 55° 5°C (131° 9°F).
Place the machine controls at the following settings: Power Mode, engine speed dial "10" and AEC switch OFF.Reference: Make reference to Testing And Adjusting, "Operational Checks" for engine rpm settings.Note: Normal operations of the engine and pumps are necessary for the pressure adjustments. If the results of the pressure adjustment are not correct, then the engine and the pump characteristic curve needs to be checked. Slow output flow from the pump is an indication of air in the hydraulic system. Make sure that no air is present in the hydraulic system. Refer to Testing And Adjusting, "Hydraulic System Pressure - Release".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.
Illustration 3 g00341013
Top of main control valve (4) Adjustment screw (5) Locknut (6) Main relief valve
Open the bucket until the bucket cylinder rod is at the full retraction.
Be sure that the main relief valve pressure is set at 34300 490 kPa (4975 72 psi).Note: Always make final pressure adjustments on pressure rise.
Loosen locknut (5). Turn the adjustment screw (4) clockwise for one half turn. Tighten locknut (5) .