Toyota has announced that it will conduct a voluntary Safety Recall involving approximately 740,000 U.S. vehicles, including the 2004 through 2006 Toyota Highlander (non Hybrid) and Lexus RX330, to address the possibility that a small amount of the brake fluid could slowly leak from the brake master cylinder, resulting in illumination of the brake warning lamp.

The Toyota genuine brake fluid used during vehicle assembly for vehicles sold in the United States contains polymers. The polymers act as lubricants for certain brake system components. If during vehicle maintenance, brake fluid is used that does not contain such polymers or only small amounts, a part of the internal rubber seal (brake master cylinder cup) located at the end of the brake master cylinder piston may become dry and may curl during movement of the piston. If this occurs, a small amount of the brake fluid could slowly leak from the brake master cylinder into the brake booster, resulting in illumination of the brake warning lamp.

If the brake warning lamp has illuminated and the vehicle continues to be operated without refilling the master cylinder brake fluid reservoir, the driver will begin to notice a spongy or soft brake pedal feel and braking performance may gradually decline.

Owners of the involved vehicles will be notified by first class mail beginning in early November 2010. Toyota and Lexus dealers will replace the brake master cylinder cup with a newly designed one at no charge to the vehicle owners.