Hello
i have a 2015 g37 conv with sports optipn
it has 20,000 miles on it
it really only gets driven once a week or so
the other sub freezing morning I hopped in my car and when I backed out of driveway the brakes went to the floor,
i pumped the brakes a couple times and the brakes felt
like normal again. So I continued driving and again the brakes felt like it went to floor
i pumped brakes and they went back to normal.
so I drove home and checked brake fluid, it was fine, I looked for any leaks, there were none?
could this be a sensor of some kind that went out that is causing this ?
if it is the master cylinder, it would be leaking wouldn't it? Could it be air in brakes? How does air get in brake line?
im taking it to mechanic Monday, but this has me puzzled
thanks in advance
Clay

 

As a SWAG: might be your antilock modulation block.

 

My money is on the brake booster, or master leaking internally.

 

Clay, were you able to figure out what the issue is?