Stop in for a cup of coffee

Need to do a thorough check and bleed my brakes... Was heading to the show today and pedal went WAY further than normal, thought I wasn't going to get her stopped. :eek: Opened the master cyl and both sections were low, small section near empty. I looked around underneath really good and didn't see anything wet, so pretty sure it's been a gradual loss. Was close to Advance auto, so got a quart and filled it up. Either way, it got low enough that I have air in them now..
The smaller section is for your rear brakes.
I bet your rear wheel cylinders are leaking.
Pull the wheels and check it out.
Could be the master cylinder itself,check fluid leak on back of master cylinder and under it.