Is it possible to be sucking air into the brake system without loosing fluid? I bleed my brakes and I just keep getting bubbles. Ive bleed them three times now a total of like 20 times on each caliper. Everything was fine till one day the pedal just started sinking and there was no fluid lose what so ever. Im just pulling air in i think. When i step on the brake i can here air comming out of the resivour cap it seems under that center thing on the cap where the wires go into it could i be pulling air in there? Should I hear air releasing from the cap cuase i think its sucking it back in too.

Sounds like your master cylinder on your brakes went out. If so, buy the Toyota replacement and not Auto Zone, your future self will thank you......

^ Jordan sounds like he's got it.

-shaeff