What caused me to put DOT 5 in the Toyota in the first place was the fact that within 3000 of the time I bought it at 40K, the front and the rear brakes had both leaked, and of course then I had to change BOTH cyinders and BOTH calipers and so when the master cylinder started to leak, I said the hell with this and flushed the system and put the DOT 5 into it. Perhaps the problem was the quality of the rubber brake parts made for the Toyotas.
I have had no problems with the brakes on either Mercedes and have since begun to drain and replenish the DOT 4 fluid every 2 years.
Before this, I had never heard that brake fluid ever needed replacing. It seemed pretty nasty looking to me, and I suggested that it needed to be changed, but the mechanics would just say īt just gets like that".
Of course this was back when the mechanics I came in contact with were pretty much 8th grade dropouts.
I have never had a problem with boiling brake fluid or brakes fading: not too many mountains in FL.
Semibodacious Transmogrifications a Specialty
1990 300D 2.5 Turbo sedan 171K (Rudolf)
1985 300D Turbo TD Wagon 219K (Remuda)
"Time flies like and arrow, yet fruit flies like a banana"