LEVER GP-CONTROL VALVE 2108917 - Caterpillar

Table 2
Accumulator Precharge Pressure/Temperature Relationship for the
6900 kPa (1000 psi) Service Brake Accumulators    
Temperature     Pressure    
-7°C (20°F)    
5000 kPa (726 psi)    
-1°C (30°F)    
5105 kPa (741 psi)    
4°C (40°F)    
5235 kPa (760 psi)    
10°C (50°F)    
5340 kPa (775 psi)    
16°C (60°F)    
5420 kPa (787 psi)    
21°C (70°F)    
5500 kPa (798 psi)    
27°C (80°F)    
5605 kPa (813 psi)    
32°C (90°F)    
5735 kPa (832 psi)    
38°C (100°F)    
5840 kPa (848 psi)    
43°C (110°F)    
5920 kPa (859 psi)    
49°C (120°F)    
6000 kPa (871 psi)    
Illustration 3 g00107133
Nitrogen Charging Equipment (1) Nipple. (2) Coupling assembly. (3) Pressure gauge. (4) Hose assembly. (5) Coupling assembly. (6) Nipple. (7) Valve. (8) Pressure gauge. (9) Regulator assembly. (10) Pressure regulating screw. (11) Chuck for the nitrogen cylinder valve. (12) Valve handle. (13) Chuck. (14) Hose assembly.
Apply the service brakes 20 to 30 times. This will release any pressure that may be in the brake accumulators.
Illustration 4 g00804708
Brake Accumulator (17) Bolts. (18) Washers. (19) Bracket.
Remove the bolts (17) and the washers (18). Remove the bracket (19) .
Illustration 5 g00475898
Brake Accumulator (15) Cover. (16) Cap.
Remove cover (15) from the brake accumulator. Remove cap (16) from the valve assembly on the brake accumulator.
Use a 0 to 13800 kPa (0 to 2000 psi) pressure gauge (8) to check the nitrogen charge in the brake accumulator.
Install chuck (13) onto the nitrogen charging valve for the brake accumulator.
OPEN valve (7) and charge line (14) to the correct precharge. Refer to Table 2.
Turn valve handle (12) 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 (7) 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 (7) .
CLOSE valve (7) and OPEN the valve on the nitrogen cylinder. Adjust screw (10) on regulator assembly (9) until pressure gauge (3) is at the correct charging pressure. Refer to Table 2 for the correct charging pressure.
OPEN valve (7) and charge the brake accumulator. Then, CLOSE valve (7). If pressure gauge (8) and pressure gauge (3) show the same reading and the readings do not change, the brake accumulator has the correct charge.If the pressure reading on gauge (8) decreases, OPEN valve (7) and allow more nitrogen to fill the brake accumulator.Perform this procedure until pressure gauge (8) and pressure gauge (3) show the same reading. Make sure that neither reading changes when valve (7) is closed.
CLOSE valve (7). CLOSE the valve on the nitrogen cylinder.
Turn valve (12) on chuck (13) OUTWARD in the counterclockwise direction. Remove the test equipment.
Perform this procedure for the other brake accumulator.Charge Procedure for Rebuilt Brake Accumulator
It is necessary to remove all