Driving a 2007 Volvo S40, automatic transmission.
As title states, my braking pedal sometimes goes to floor during driving, mainly when I'm in a traffic jam and using the brakes actively. It also happened a few times while driving on highway at higher speeds, so the first 40-50% of pedal travel it looks like it doesn't brake at all, then it brakes, but it's not even close to the "usual braking" feeling that happens when it's working as it should and at like 20% pedal travel I instantly feel like the car is actually going to stop.
Unusual things that happened these days was that my car got raised on a stand and the engine was running, so as the car was "floating" the ABS light turned on, but after driving on road for a couple seconds it turned off.
So the biggest issue is why does the pedal go to floor only sometimes (like if it was something horrible there, it would probably always go to floor).
This is probably a pretty stupid question, but it's my first car and I'd rather look stupid online than hit an utility pole.