Cause of sudden brake failure ???
 

1998 S70 - my son has been adding brake fluid due to a minor leak.....brakes went out suddenly on my wife....the fluid reservoir was empty. topped it off but still no brakes....could this be as simple as there being air in the lines? and if so, do i need to bleed out brake fluid while adding to get the air out? or do something else?

Thanks for your advise....

you need to fix the leak than bleed the air out of the brakes

+1 Fix the problem. Until you do, please let me know where you guys drive and what the car looks like so I can make sure you are not behind me.