Which c17 hydraulic systems do you use to change the primary brake system?

To change the primary brake system on a C-17, the hydraulic systems utilized are primarily the Utility Hydraulic System and the Brake Pressure Control System. The Utility system provides hydraulic pressure necessary for brake operation, while the Brake Pressure Control System manages the distribution of that pressure to the brakes. Additionally, the Auxiliary Hydraulic System may be engaged for backup functionality. Proper procedures must be followed to ensure safety and effectiveness during the brake system change.