Brake fluid change?

Gjac wrote:
I don't know how many on here remember honing the wheel cylinders for drum brakes back in the 60's with a honing tool inserted into an electric drill. When you removed the rubber ends and run your fingernail inside the cylinder you could feel where the ID of the steel had been etched away from the moisture. The depth of etched valleys were deep enough to cause the rubber seal to leak brake fluid all over the brakes, which to me is serious for a 20-30k lb MH coming down a steep hill. I don't change mine every 2 years, I have a Chevy chassis but have changed it probably 3-4 times over the last 15 years. What I do is jack up the front end and gravity drain the fluid starting in the rear the working my way to the front. I suck out the old fluid from the MC first with a turkey baster and add new fluid so only the lines have old fluid. When the fluid comes out clean I close the bleeder and open the next one. I can do this job myself and it does not take as long as it sounds.

never honed a brake cylinder on drum brakes but did need to replace a few even though I flushed the brakes every year or so.

Today, gone are drum brakes, gone are the days when car brakes could do ONE panic stop from about 60mph before fade set in. So... now brakes have more reserve, doesn't mean moisture doesn't affect them, just means it doesn't show up as quick but the failure is the same when it happens from water in the fluid.

Water molecules are very small, you can make things "air tight" so that Nitrogen or Oxygen molecules won't go through but that doesn't mean they are "water tight" H2O molecules are much smaller. Water vapor can migrate through many plastics and rubber hoses and contaminate the brake fluid.