As the title suggests my 2007 Mazda3 has brakes that have recently gone squishy. Obviously this is a huge safety problem so I'm not driving it until I can get it sorted out. When applying the brakes the pedal feels squishy and travels further than normal, but does slow the car down. If I pump the pedal a couple of times it firms up and feels normal until after it's released. I checked the brake fluid reservoir and looks like it might be very low. Hard to tell for sure until I try adding more fluid up to the max line. This is the 5 speed MT and there are no issues with the hydraulics for the clutch as far as I can tell. I also took a quick look at the rear bleeder valves since I can get to them pretty easily without jacking the car up. I removed the cap for the rear driver's side bleeder valve and it was wet, apparently with orange looking brake fluid. Is that expected, or could this be where I'm losing pressure/brake fluid? Also I noticed this bleeder was nice and shiny looking. Not sure if that's because of the cap that's been protecting it, or because it's been soaking in brake fluid for who knows how long. The bleeder on the other side unfortunately has the cap missing and is rusty (and dry). Any ideas on how to diagnose this?