LATCH AS 1594950 - Caterpillar

Test Preparation - Accumulator Preliminary Test
Clear all personnel from the machine and from the area around the machine.
Start the engine.
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Engine speed dial
Set the engine speed dial at "10".
Lower the left console.
Position the machine on level ground. Check the visibility and adjust the mirrors for the best vision close to the machine.
Fully depress the service brake pedal until the service brake pedal locks mechanically.
Increase the hydraulic oil temperature to 46° to 60° C (115° to 140° F).
Lower the rail axles in order that all tires are fully off the ground, and shunt the road mode.Test Procedure - Accumulator Preliminary Test
Position the implements 1 m (3.3 ft) from the ground.
Shut off the engine by turning the start switch to the OFF position. When the engine has stopped, return the start switch to the ON position.
Move the joysticks to lower the implements. When the accumulator circuit is functioning properly, there will be enough stored energy for approximately one minute after a power loss. This stored energy is used to lower the implements to the ground safely.
If the preliminary test fails and the implements are unable to be lowered to the ground safely after a power loss, proceed to test the accumulator circuit.Testing and Charging the Accumulator (Nitrogen Gas Charge)
Note: Some accumulators do not have a charge pressure port. This type of accumulator cannot be recharged. The accumulator must be replaced. Replacement accumulators are equipped with a charge pressure port.
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Cap for charging port on accumulator
Pressurized System!Hydraulic accumulators contain gas and oil under high pressure. DO NOT disconnect lines or disassemble any component of a pressurized accumulator. All gas pre-charge must be removed from the accumulator as instructed by the service manual before servicing or disposing of the accumulator or any accumulator component.Failure to follow the instructions and warnings could result in personal injury or death.Only use dry nitrogen gas to recharge accumulators. See your Cat dealer for special equipment and detailed information for accumulator service and charging.
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, "Dealer Service Tool Catalog" for tools and supplies suitable to collect and contain fluids on Cat® products.Dispose of all fluids according to local regulations and mandates.
Refer to Special Instruction, REHS5464, "Accumulator Discharging and Charging Procedures" for the required tooling, and the testing and charging procedure.Note: Do not attempt to charge the accumulator until all pressure has been removed from the pilot manifold accumulator.
Refer Table 1 for the correct charge pressure.Test Preparation - Check Valve (Pilot Manifold)
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Pilot manifold
(1) Plug
(2) Check valveIf check valve (2) does not close properly during a loss of pilot pressure, the accumulator precharge pressure will exhaust before being able to provide lowering of the implements.Note: Make sure that the accumulator has a proper nitrogen gas charge before attempting to test check valve (2). An improperly