A system for a vehicle is disclosed. The system may include an accumulator, a pump, and a controller. The controller may be configured to, responsive to braking of the vehicle, close a line pressure regulator to isolate the accumulator and pump from a transmission pressure line demand, and operate the pump to charge the accumulator without satisfying any of the demand, and responsive to a tip-in event, open the line pressure regulator and operate the accumulator and pump to satisfy the demand.