LEVER 4H7798 - Caterpillar

Personal injury or death can result from sudden machine movement.Sudden movement of the machine or release of oil under pressure can cause injury to persons on or near the machine.To help prevent possible injury, perform the procedure that follows before testing and adjusting the hydraulic and steering system:
Care must be taken to ensure that fluids are contained during performance of inspection, maintenance, testing, adjusting and repair of the product. Be prepared to collect the fluid with suitable containers before opening any compartment or disassembling any component containing fluids.Refer to Special Publication, NENG2500, "Caterpillar Tools and Shop Products Guide" for tools and supplies suitable to collect and contain fluids on Caterpillar products.Dispose of all fluids according to local regulations and mandates.
Implement Hydraulic System
Move the machine to a smooth horizontal location. Move away from working machines and from personnel. Lower implements to the ground.
Permit only one operator on the machine. Keep all other personnel away from the machine. Keep all other personnel within the view of the operator.
Engage the parking brake.
Turn off the engine.
Move the implement control levers to all positions in order to release the pressure in the hydraulic system.
Engage the service brakes several times in order to release the pressure in the brake system.
Carefully loosen the filler cap on the hydraulic tank in order to release the pressure in the tank.
Make sure that all hydraulic pressure is released before any fittings, any hoses, or any components are loosened, tightened, removed, or adjusted.
Tighten the filler cap on the hydraulic tank.
When the pressure in the system has been relieved, the lines or the components can be removed.Note: During a diagnosis of the implement hydraulic system, remember that correct oil flow and correct oil pressure are necessary for correct operation. Oil pressure is caused by a resistance to the flow of oil.Procedure
When you perform the diagnosis of a problem with the implement hydraulic system, follow this procedure.Perform visual checks in Testing and Adjusting, "Visual Inspection" first. If you complete the visual checks and the problem is not identified, perform the operation checks under Testing and Adjusting, "Operation Checks".This procedure can help identify problems with the implement hydraulic system. When the problem is defined, refer to Testing and Adjusting, "Implement and Steering Hydraulic System - Troubleshooting". The troubleshooting section lists the probable causes of a known problem. Because more than one cause may exist for a problem, the troubleshooting section may call for specific inspections or for specific instrument tests. These inspections and tests help with the identification of the most probable causes.During diagnoses of the hydraulic system, remember that correct oil flow, correct temperature, and correct oil pressure are necessary for correct operation. The maximum pump output (oil flow) increases with an increase in engine rpm. Also, the maximum pump output decreases when the engine rpm decreases. Oil pressure is caused by a resistance to the flow of oil.Use the following instruments in order to perform basic tests: 4C-4890 Hydraulic Test Group, 8T-5320 Hydraulic Test Group, a stopwatch, a magnet, a