YRV Turbo Needs Reluctor Ring


My Lil YRV turbo just covered 40000 miles, replaced the discs and pads and now
Noise occurs when braking at slow speeds
Pedal fluctuation (like brake judder)
I have had this problem before on an old Rover but have found no nifo of this happening on the YRV nor can i find the replacement part
any help would be great