When the temperature is below 32 degrees (freezing level), anytime I push on the brakes and the car (GS300)dives as I'm slowing down, the sloshing action of the brake fluid in the reservoir moves around, below the minimum level for fluid, and the "Brake" light turns on in my car. It's the same warning light that turns on when you have the emergency brake down. This only happens when the outside temperature is below freezing though. When the car is at rest, the reservoir is somewhere between the "Min" and "Max" line, but closer to "Min". I was by my friend's shop the other day asking if he had some brake fluid for me to add to the reservoir, he simply said "don't do it". He told me to leave it alone, as it will cause a negative effect on the braking in my car. He said only change it when I decide to change the brakes. My brakes are fine, the car stops perfectly(knock on wood), but that brake light is really annoying. Anybody?
Ed

 

assuming your friend has a compatible brake fluild (Dot3 or higher), I dont' see why you get any negative effect by adding a bit more fluild. The manual stated, that you have to pump the brake 10-15 times before you check the fluild. check your manual. I havent hear anyone get a problem by adding fluid in to their brake as long as the level is still under MAX. Even the Lexus manual called for checking and add the fluid if needed.

 

i'd add fluid til just below the max line. i had the darn brake light coming on in cold mornings too, but i believe my pads were just worn.

 

top it up.............