Does brake fluid dry up?

[berniedd]

The question may be laughable, but it's been 6 years since I last checked the brake fluid level in the 1998 CRV. Nine months ago, I discovered I was low on brake fluid, so low that the master cylinder almost was ready to suck in air. I filled her up and today (9 months later) the level has not changed any. There are no leaks I can see anywhere. If there's a leak, I would have seen lower brake fluid level by now.

Some may opine that the brake fluid in the MC was less as the pads wore down and the pistons moved further out their bores and took in more brake fluid as they did so. But I'd replaced brake pads 11 months ago and pushed in the pistons with my C-clamp, thus pushing the brake fluid back up into the MC. (I didn't check the brake fluid level at that time.) All the calipers were bone dry when I did the job.

Anybody with ideas on where my brake fluid went?

 

[FermeLaPorte]

Thats just what happens with daily use, even if there are no leaks

 

[BrocLuno]

9 years without flushing the fluid ... Hard braking down hill can boil the fluid because there is water being absorbed all the time. Brake fluid absorbs water slowly, but after nine years, it was pretty wet. Would not take much to boil that ...

Brake fluid should be flushed every three years or so

 

[MolaKule]

Originally Posted By: BrocLuno
9 years without flushing the fluid ... Hard braking down hill can boil the fluid because there is water being absorbed all the time. Brake fluid absorbs water slowly, but after nine years, it was pretty wet. Would not take much to boil that ...

Brake fluid should be flushed every three years or so

Absolutely.