Typically, the fall of the brake fluid level on RAV4 is related to the wear of brake pads. As the brake pads wear the brake mechanism when worn, the volume of the hydraulic actuator is also increasing, causing a drop in the level in the bachet. It is also necessary to check the leak of liquid at the entire brake line.
If the level is very low and there are no trace leaks, then the most likely cause of the malfunction is the hydacuvacus amplifier. Most likely, the cuff that the liquid goes through.
