Anyone else having problems with the Category 5 tests and the MX10 machines not being able to hold 125% capacity with just the primary brake?

Trying to order new brake pads from Kone Spares and they say you need to replace the entire brake to the tune of 5000 bucks each. crazy... before we try that expensive option, want to make sure i'm not missing something. the car drifts as soon as its at 125%. it doesn't look like I can adjust the brake voltage either, which I figure increasing the voltage a bit could help.