VALVE-PRESSURE 1876458 - Caterpillar

Use the following Steps in order to test or check the appropriate relief valve setting:
Lower all of the work tools and the stabilizers to the ground.
Stop the engine.
Turn the key to the ON position and move all of the control levers to all of the positions. This will release the system pressure.
Turn the key to the OFF position.
Remove the line relief valve that will be tested.
Illustration 5 g01296672
Secure 288-6823 Manifold (E) in a suitable holding device.
Install two 030-8370 Adapters (G) and two 1P-2375 Couplers (H) in 288-6823 Manifold (E) .
Attach two 1P-2376 Adapters (J) to two 8F-0024 Hose Assemblies (K) .
Install line relief valve (F) in 288-6823 Manifold (E) .
Connect two 8F-0024 Hose Assemblies (K) , two 3B-7722 Bushings , and 7J-8611 Elbow to 3S-6224 Electric Hydraulic Pump .
Connect 8T-0860 Gauge to 3S-6224 Electric Hydraulic Pump .
Turn the 3S-6224 Electric Hydraulic Pump to the ON position. Check for leaks at the connection.
The 3S-6224 Electric Hydraulic Pump only has a 7.6 L (2 US gal) reservoir. Pump damage may result if the pump is operated with an empty reservoir.
Slowly increase the pressure. Record the pressure, when the line relief valve opens. Compare this pressure to Table 3.
Stop the pump.
Table 2
Line Relief Valve Pressure Settings     Actual    
Hydraulic Circuit     420E, 430E, 432E, 434E, 442E, and 444E        
Rod End for STICK OUT    
29000 kPa (4206 psi)        
Head End for STICK IN    
Extendable Stick (if equipped)
Rod End for retracting the stick    
26500 kPa (3844 psi)        
Auxiliary for backhoe (if equipped)
Head end and Rod end    
26500 kPa (3844 psi)        
SWING
Swing LEFT
Swing RIGHT    
27000 kPa (3916 psi)        
Backhoe BUCKET DUMP    
31500 kPa (4569 psi)        
Backhoe BUCKET CLOSE    
BOOM RAISE    
31500 kPa (4568 psi)        
BOOM LOWER    
16500 kPa (2393 psi)        
Loader Rod End for the Dump Operation     Single Tilt
29000 kPa (4206 psi)        
Parallel Lift
27500 kPa (3989 psi)    
Loader Rod End for the Dump Operation
434E and 444E     Single Tilt machines
31500 kPa (4569 psi)        
Head End for the Tilt Back Operation of the Loader     Parallel Lift
16500 kPa (2393 psi)        
Single Tilt
19000 kPa (2756 psi)    
Auxiliary (if equipped) for the Loader
Line valve for the Head End
Port B    
24500 kPa (3553 psi)        
Illustration 6 g01296607
Line Relief Valve (A) Cap (B) Screw for Adjusting (C) Locknut
If the line relief valve is within the specification, then go to Step 18. If the line relief valve is not within the specification, then an adjustment is required.
Remove cap (A) . Loosen locknut (C) and turn adjusting screw (B) clockwise in order to increase pressure. Turn adjusting screw (B) counterclockwise in order to decrease pressure.
Check the oil level in 3S-6224 Electric Hydraulic Pump and refill the oil if it is