Date registered: Dec 2005
Vehicle: W211 E320 Bluetec R129 SL500 - $1300 car ........ Ford F350 6l
Location: CA Bay Area
Mentioned: 9 Post(s)
Quoted: 1070 Post(s)
Maybe my experience will help?
I used to own gasoline-powered motorhome with carburated engine and brake lane making loops in the engine compartment.
Once, while climbing to 14,000' elevation in Colorado, my engine warmed up the compartment so much, that it boiled the gasoline in fuel line, giving me "fuel vapor lock". So the engine died and at very slow speed, I stopped and starter rolling backward. In this moment I pressed the brake pedal, only to discover that I had "brake fluid vapor lock" as well. Pedal went to the floor, why motorhome kept on rolling backward. With the help of emergency brake and transmission lock, I was able to roll on the shoulder and stop right before sharp turn with about 1500' drop at the barrier.
After about 20 minutes wait, everything cooled down and I was able to continue.
Not only flushed my brakes, when I got home, but sold the motorhome as well.
In another words, brake failure because of bad fluid don't happen very often, but can't imagine good moment for it.
In CA we don't have much moisture, so I don't hesitate to keep the brake fluid for 5-6 years, but it is cheap enough. Now with MityVac pump helping me, I might do it even more often.