CONNECTOR AS 1488342 - Caterpillar

Stop the engine. Depress the brake pedal repeatedly until there is no brake pressure.To ensure that the nitrogen charge is correct, each brake accumulator piston must be at the bottom of the accumulator cylinder. Nitrogen gas pressure varies with the temperature. To obtain the most accurate nitrogen charge, the temperature of each accumulator must be identical to the air temperature around the accumulators.If an accumulator has less than half of the required amount of precharge pressure, use the following procedure to recharge the accumulator. This procedure prevents trapping a quantity of oil in the accumulator which will give an inaccurate precharge reading.
Charge the accumulator.
Operate the service brakes several times.
Charge the accumulator again.However, the temperature of the accumulators could be higher than the air temperature around the accumulators. In this case, the temperature of the accumulator should be used instead of the surrounding air temperature.Note: The pressures in the following table are for an ambient air temperature of 21°C (70°F). Adjust the pressure for other ambient conditions, as required.
Table 2
Accumulator Precharge Pressure/Temperature Relationship for a Typical
6200 kPa (900 psi) Brake Accumulator    
Temperature     Pressure
6200 kPa (900 psi)    
-7°C (20°F)    
5616 kPa (815 psi)    
-1°C (30°F)    
5733 kPa (832 psi)    
4°C (40°F)    
5850 kPa (849 psi)    
10°C (50°F)    
5967 kPa (866 psi)    
16°C (60°F)    
6084 kPa (883 psi)    
21°C (70°F)    
6201 kPa (900 psi)    
27°C (80°F)    
6318 kPa (917 psi)    
32°C (90°F)    
6435 kPa (934 psi)    
38°C (100°F)    
6552 kPa (951 psi)    
43°C (110°F)    
6669 kPa (968 psi)    
49°C (120°F)    
6786 kPa (985 psi)    
Illustration 3 g00495846
Nitrogen Charging Equipment (5) Nipple. (6) Coupling assembly. (7) Pressure gauge. (8) Hose assembly. (9) Coupling assembly. (10) Nipple. (11) Valve. (12) Pressure gauge. (13) Regulator assembly. (14) Pressure regulating screw. (15) Chuck for the nitrogen cylinder valve. (16) Valve handle. (17) Chuck. (18) Hose assembly.
Illustration 4 g00916229
Brake Accumulator (19) Cover. (20) Cap.
Apply the service brakes 20 to 30 times. This action will release any pressure that may be in the brake accumulators.
Remove cover (19) from the brake accumulator. Remove cap (20) from the valve assembly on the brake accumulator.
Use a 0 to 13800 kPa (0 to 2000 psi) pressure gauge (12) to check the nitrogen charge in the brake accumulator.
Install chuck (17) onto the nitrogen charging valve for the brake accumulator.
OPEN valve (11) and charge line (18) to the correct precharge. Refer to Table 2.
Turn valve handle (16) completely in the clockwise direction. Check the temperature of the air around the brake accumulator. The reading on the pressure gauge must be within the tolerances in Table 2.
If the reading on the pressure gauge is too high, slowly OPEN valve (11) in order to lower the pressure. If the reading on the pressure gauge is too low, use the following procedure to charge the brake accumulator:
Connect a hose from the nitrogen cylinder to valve (11) .
CLOSE valve (11) and OPEN the