While going through a presentation on the Airbus WIN application with regard to cost saving practises. It was told with regard to brake life. If the parking brake was applied when the brake temperatures were still high that it can contribute to the dragging brake phenomenon.
Could someone help explain how does this happen ?
Why is it not recommended to leave the parking brake ON with hot brakes?
The SOP recommends to set the parking brake brake back to OFF once the chocks are in place when the brakes are hot (refer to FCOM for temperature values). This is to prevent transmitting heat to the brake pistons potentially causing seal degradation, hydraulic fluid overheating and generation of a black aggregate, that can reduce the piston running clearance and then lead to brake dragging.
(bolded for emphasis)
