BRAKE G 0546673 - Caterpillar

13. Open needle valve (1) and measure the length of time it takes pressure gauge (2) to read charge pressure. The charge time should take only 10 to 20 seconds. If the gauge instantly reads the correct charge pressure, the compressed gas was not relieved correctly from the gas chamber in Steps 1 through 8. Go back to Step 1 and repeat the procedure until the gas has been completely relieved from the system.14. Turn the nitrogen gas off, but leave the line connected. This will ensure that the accumulator piston is bottomed out and that the gas chamber is completely full of nitrogen gas.15. Turn the ride control switch to the OFF position. Raise the lift arms and hold the control lever in the RAISE position for five seconds. This will make the system reach and maintain the implement relief valve setting.16. The gas pressure gauge should indicate implement hydraulic system relief pressure. If a lower pressure is indicated at this time, the accumulator has not been fully charged and the procedure must be started again.17. Lower the bucket to the ground. Watch the pressure gauge, and move the ride control switch to ON. The gas pressure should drop immediately. An empty bucket will have a tendency to raise. This action indicates the ride control function is operating correctly.18. If the gas pressure has not dropped to the charge pressure, go back to Step 1 and repeat the procedure.19. Remove the nitrogen charging group and replace the protective cap on the gas charge valve assembly.20. Replace the guard over the gas charge valve.Rebuilt or New Accumulator Charge Procedure
Make reference to on first page of Hydraulic System Testing and Adjusting section.
It is necessary to remove all the air from the nitrogen end of the accumulator. When the accumulator is new or rebuilt, put approximately 1.9 liters (2 quarts) of SAE hydraulic oil in the nitrogen end of the accumulator. This oil will be used to help remove air from the nitrogen end of the accumulator and also to put lubricant at the top seal of the accumulator piston.
NITROGEN CHARGING GROUP
(1) Needle valve. (2) Pressure gauge. (3) Quick disconnect coupling (male). (4) "T" handle. (5) Chuck. (6) Pressure gauge. (7) Connection to nitrogen cylinder valve. (8) Pressure regulating screw. (9) Regulator Assembly. (10) Quick disconnect coupling (female). (11) Quick disconnect coupling (male). (12) Hose assembly. (13) Quick disconnect coupling (female).1. Attach gas chuck (5) to the accumulator gas charge valve. Join male and female quick disconnect couplings (3) and (13). Put the open end of hose assembly (12) in a container.2. Open needle valve (1) and turn "T" handle (4) on gas chuck (5) all the way in (clockwise).3. With the accumulator mounted in an upright position move the accumulator piston fully to the nitrogen end of the accumulator.
Accumulator (Typical Example)4. As the accumulator piston moves to the top of the accumulator, the air and then the oil will be pushed out of the nitrogen end of the accumulator