Brake Fluid Leak problems of the 2003 Toyota Tundra

I am a retired Toyota master diagnostic technician. I had to replace my rear brake lines on my 2003 Tundra-with 79,962 miles. The rear brake lines have rusted through which had to be replaced- at my expense. My brakes failed as I was towing a trailer in heavy, city traffic. I was going 35mph when a vehicle pulled out in front of me and then proceeded to stop suddenly to make a left turn into a parking lot. I slammed on the brakes and the pedal went to the floor. I was lucky there was room to maneuver to the right so I was able to avoid hitting the vehicle in front of me. I'm sure there have been those less fortunate. Then, as I was replacing the lines, I saw a fluid leak under rear of vehicle. Upon inspection I found the rear differential housing has rusted so badly that the gear oil is leaking through the housing. Unfortunately the only remedy is the replacement of the complete rear axle/differential assembly. Also the power steering lines have also rusted through which also had to be replaced- at my expense. The frame has already been replaced-under recall. It is obvious that the material that was used is of very low quality causing very dangerous situations. Ie; loss of vehicle control due to differential lock-up, loss of vehicle braking due to rapid fluid loss, loss of vehicle steering control due to rapid fluid loss. I am amazed that Toyota motor CO. Will not stand behind the product they sold-without being forced to. One quick look under a 2003 Tundra is all it takes to see that low/poor quality hardware and materials were used. Without repair and/or replacement of above stated components someone will get injured-possibly fatally. Please investigate these complaints as soon as possible. These components should last for the lifetime of the truck. A differential is not an item one expects to ever replace-"sorry but your warranty's expired". Thank you. Sincerely,.