BODY 1357477 - Caterpillar

Specification
Gas pressure is variable with temperature. Check the temperature of the air around the accumulator. In order to check the amount of charge in an accumulator, the accumulator must be at the same temperature as the surrounding air.Note: The temperature of the accumulator may change as the accumulator is being charged due to the expansion or compression of the nitrogen charge. Charging the accumulator in several steps may be necessary in order to ensure a correct charge.
Table 1
"Accumulator (Boom Dampening) - Test and Charge"
Date: Machine Serial Number:
Item Load/Application(1) Actual
Low Weight Standard Heavy Weight
Boom Dampening Accumulator 8,500 to 9,500 kPa (1,233 to 1,378 psi) 11,500 to 12,500 kPa (1,668 to 1,813 psi) 14,500 to 15,500 kPa (2,103 to 2,248 psi)
(1) The boom dampening accumulator charge pressure was tested at 20° C (68° F)Introduction
The following procedure will determine if the accumulator for the boom dampening system is charged to the appropriate pressure. The accumulator is located on the boom cylinder.
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.
Machine Preparation
Clear all personnel from the machine and from the area around the machine.
Start the engine.
Illustration 1 g02449876
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 80° C (115 to 176° F).
Lower the stabilizers and the blade tip.
Fully extend the bucket cylinder and place the worktool on the ground.
Stop the engine.
Release the pressure in the hydraulic system. Note: Refer to Testing and Adjusting, "System Pressure - Release".
Turn the start switch to the ON position. Testing and Charging the Accumulator (Nitrogen Gas Charge)
Illustration 2 g03732780
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 boom dampening accumulator.
Refer Table 1 for the correct charge pressure.