ENGINE AR-COMPL 20R5354 - Caterpillar

When testing and adjusting the hydraulic system, move the machine away from job traffic pattern and away from personnel. Allow only one man on the machine. Keep all other personnel off to one side and within view of the operator.
Visual Checks
A visual inspection of the system should be the first step when troubleshooting a problem. Perform the following inspections with the engine stopped and equipment lowered to the ground.1. Check the oil level. Slowly loosen the tank filler cap. If oil comes out the bleed hole when the filler cap is loosened, allow tank pressure to bleed off before removing the cap.2. Remove the filter elements and check for foreign material. A magnet will separate ferrous metal material from non-ferrous metal and non-metallic sealing material (piston rings, O-ring seals, etc.).3. Inspect all lines and connections for damage or leaks.4. Inspect all lines and all cylinders for damage or external leakage.5. Inspect the control linkages for bent, damaged or broken components.Operational Checks
The operational check of the system is useful in detecting possible internal leakage, faulty valves or a faulty pump. Refer to the OPERATIONAL CHECK LIST for the "problems" and "probable causes" outlined.Operational Check List
PROBLEM: Noisy pump, erratic cylinder movement and/or excessive oil foaming. PROBABLE CAUSE:1 -Air leak on inlet side of pump.2 -Worn pump.3 -Incorrect oil viscosity.4 -Low pressure relief valve setting. PROBLEM: Overheating. PROBABLE CAUSE:1 -Incorrect oil viscosity.2 -Overloading system.3 -Worn pump.4 -Line restriction.5 -Incorrect pressure relief valve setting. PROBLEM: Pump not delivering sufficient oil. PROBABLE CAUSE:1 -Low oil level.2 -Oil viscosity too high.3 -Pump assembled incorrectly.4 -Worn pump. PROBLEM: Low oil pressure. PROBABLE CAUSE:1 -Low pressure relief valve setting.2 -Vanes stuck in pump rotor.3 -Faulty control valve.4 -O-ring seal failure in circuit.5 -Pump assembled incorrectly. PROBLEM: Slow cylinder movement. PROBABLE CAUSE:1 -Low pump output. a. Worn pump.b. Pump assembled incorrectly.2 -Low pressure relief valve setting.3 -Cylinder piston seal failure.4 -O-ring seal failure in circuit. PROBLEM: Excessive cylinder drift. PROBABLE CAUSE:1 -Worn piston seal rings.2 -Worn valve spool.3 -Make-up valve not seating properly. (On internal valve circuit only.)4 -O-ring seal failure in circuit.Hydraulic System Test Procedures
Pump
Check the pressure relief valve setting. Refer to the topic TESTING THE PRESSURE RELIEF VALVE. Check the relief valve setting at LOW IDLE. If the relief valve pressure can be obtained at low idle, the pump is delivering sufficient oil flow.If the machine is equipped with two or three circuits, determine if relief valve pressure can be obtained at low idle in all circuits. If the pressure cannot be obtained in any of the circuits, the pump or relief valve is probably bad. If the pressure cannot be obtained in only one circuit, refer to the drift tests for further testing. Tool Bar Circuit Drift Test
TEST NO. 1: Raise the rear of the machine off the ground by