DRIVE GP-ACCESSORY 4P0853 - Caterpillar

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.
Dry nitrogen is the only gas approved for use in the accumulators. The charging of oxygen gas in an accumulator will cause an explosion. An explosion can be eliminated by using nitrogen gas cylinders with standard CGA (Compressed Gas Association, Inc.) No. 580 connectors. When nitrogen gas is ordered, make sure to order the cylinders with CGA No. 580 connectors.Do not rely on color codes or other methods of identification to tell the difference between nitrogen and oxygen cylinders. In any application, never use an adapter to connect your nitrogen charging group to a valve outlet used on both nitrogen, oxygen, or other gas cylinders. BE SURE YOU USE DRY NITROGEN (99.8% purity).
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.
Specifications
Table 1
Charging Pressure for the Accumulator at Different Oil Temperatures
Temperature Pressure
−7° C (20° F) 1550 kPa (225 psi)
−1° C (30° F) 1587 kPa (230 psi)
4° C (40° F) 1618 kPa (235 psi)
10° C (50° F) 1656 kPa (240 psi)
16 °C (60 °F) 1690 kPa (245 psi)
21 °C (70 °F) 1725 kPa (250 psi)
27 °C (80 °F) 1760 kPa (255 psi)
32° C (90° F) 1790 kPa (260 psi)
38° C (100° F) 1830 kPa (265 psi) Introduction
The accumulator supplements power train oil flow in low flow conditions. The accumulator is located underneath the fuel tank at the back of the machine.The following procedure will determine if the accumulator for the power train is charged to the appropriate pressure.Test Preparation
Move the machine to a smooth horizontal location.
Lower all of the implements.
Shut off the engine.
Turn the key to the ON position. Make sure that the implement lockout switch is turned to the UNLOCKED position. Move the implement control levers to all positions several times in order to release any pressure in the hydraulic system. Testing And Charging Procedure For The Accumulator
Illustration 1 g03676808
(1) Accumulator
(2) Transmission
(3) Valve
(4) Protector Refer to Special Instruction, REHS5464, "Accumulator Discharging and Charging Procedures" for information on testing and charging the accumulator.Reference: Refer to Tool Operating Manual, NEHS0742.