The word "recall" probably ranks right up there with certain four-letter words at Toyota headquarters. The once-proud automaker has recalled millions of automakers and suffered untold damage to its once-pristine reputation as the result of numerous safety-related problems.

The latest is today's recall of about 740,000 vehicles because of the risk that a small amount of brake fluid could leak from the brake master cylinder.

The recalled models are the  2005 through 2006 Avalon, 2004 through 2006 Highlander (non-Hybrid) and Lexus RX330, and 2006 Lexus GS300, IS250, and IS350 vehicles sold in the United States.

The company said that the brake fluid used during vehicle assembly for vehicles sold in the United States contains polymers, which act as lubricants for certain brake system components.

If during vehicle maintenance, brake fluid is used that does not contain such polymers or that contains an improper amount of polymers, a part of the internal rubber seal 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 goes on and the vehicle continues to be driven 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.

As is usual in safety recalls, owners of models not covered by the recall have complained of similar problems.

Take Jennifer of Casa Grande, Ariz. She was driving her Toyota Tacoma pickup recently as she approached another vehicle that had stopped for a stop sign.

"It appeared the brakes were working but not catching as fast as usual so I put extra pressure on the brake. Getting too close than I should be for a stop, I pushed the brake to the floor and my truck dipped a bit appearing to come to a stop but then kept rolling and hit the car in front of me," she said.

In addition to the U.S. recall, Toyota is recalling nearly 600,000 vehicles in Japan because of defective fuel pump wires and brake master cylinders. In August, Toyota recalled 1.1 million Corolla and Matrix models that it said were prone to stalling.

Besides the latest recalls, Toyota is still struggling to deal with the fall-out from earlier recalls dealing with sudden acceleration. Most recently, Allstate Insurance Co. sued Toyota seeking to recover more than $3 million that the insurer says it paid in claims for accidents linked to sudden acceleration in Toyota vehicles. has received numerous reports of accidents and near-accidents involving unintended acceleration in Toyota vehicles. One of the most recent comes from Donna of Paso Robles, Calif.

"I was driving into a parking space, I applied the brake, instead of stopping, the car accelerated, it went over a 7 inch curb, and into a Shell gas station, going through a wall and plate glass window. My foot was on the brake the whole time, Donna said. When I saw the vehicle in Truman Lewis's report of 10/07/2010 regarding Toyota it was almost identical to what happened to us."

 Read more about Toyota.