ummm.......Warlord187 said:Brake fluid should be changed every two years regardless of mileage. Remember, brake fluid absorbs water. Water doesn't compress. The older the brake fluid, the more water it has, the harder it is to compress, and the lower the boiling point temperature.
Yeah, who the hell knows what I was thinking. It's been a strange last couple of days.Great White said:ummm.......
you're right about the effect of water on the boiling point, but brake fluid is used because it is imcompressable, even more so than water.
Brake fluid is anhydrous (absorbs water, it will even pull it out of the air) and the problem with this is that the water allows the metal parts to rust in the brake system and when it boils because of high braking temperature it allows the brakes to go spongy as the water in vapour form is very compressable.
We're basically talking about the same thing, although I'm not sure where you are going with the water being hard to compress. In a closed brake system, you want a fluid that is hard to compress as it will then transfere all of the braking force applied to the pedal through the master cylinder to the calipers/shoes.