As this topic goes on about braking system...
Since recently, I noticed in my car, like after running for sometime, when brakes get hot, the brake pedal sinks like about 60-70%. But I don't loose brake fully, like could stop the car after some effort, or by pumping the pedal twice or something. Is this coz of bad brake pump washers going bad or something? Or could it be coz of air in brake oil? And do I have to fix this immediately?