my car decided to just take a big ol' chit on me today with issues out my ass. out of nowhere... anywhere in the range of 10-30 mph ROUGHLY. i can hear a "POP" from what sounds like the front drivers side of the car. it does NOT do this while stopped, below 10 mph again ROUGHLY or when over 40 mph. fluid is good, no leaking, good pads on it. everything is tight. it's only coming from one side that i can make out. booster? calipers, wtf causes this now? it causes the noise with the lightest application of the pedal. also, the pedal FEELS softer then usual. it might be in my head. the car literally developed like 5 issues today out of nowhere. thoughts?