Possible leaky brake master cylinders have led to a Toyota recall of 740,000 model year 2004 through 2006 Avalons, Highlanders (hybrid models not included) and four Lexus models: RX330, GS300, IS250 and IS350. Worldwide, an additional 799,000 vehicles are being recalled: 599,000 in Japan and 200,000 in Europe.
According to the Detroit Free Press: "Toyota said its factory-installed brake fluid contains polymers that lubricate brake components. If that original fluid is replaced with fluid that doesn’t contain the same concentration of polymers, a rubber seal in the master cylinder may dry or curl, thus creating the possibility of a leak. Drivers could experience a spongy or soft brake-pedal feel."