Does anyone know the size of the o-ring that goes on the early style S4 power steering pump where the sensor that screws in to the bottom of the pump attaches? Mine is all cracked and leaking and I was just told by mazda that it is not available seperatly from the entire pump assembly. Also does it need to be an oil resistant o-ring?

 

Measure it, then go to www.mcmaster.com. Go to the "Metric O-rings" section and buy a pack of viton orings. They're oil resistant if you're worried about to breaking down.