Does DOT5 brake fluid expire?

[Jim Bronson]

I found a partially-used bottle while cleaning up the garage, and I'd hate to waste it. It's probably 3-4 years old.

[FSG]

in the trash can it should go 

[twincam8888]

As I understand it Dot 4 absorbs moisture and Dot 5 absorbs air. In either case they don't store well, toss it.

[Jim Bronson]

OK then, in the trash it has went. Thanx!

[Hossamania]

I will use a partial bottle if I've had it a couple months for my own bike. If it has seen a winter, it gets tossed.
But if working on a friend's, new every time.

[harley_cruiser]

Like stated dot 5 is not hydrophobic, so does not absorbs water, but does absorb some air And makes it harder to bleed. If it was 3,4 or 5.1 I would toss it, but since it is silicone, send it to me and I will use it.
And when you buy new make sure it's genuine Harley dot5. 

[02roadcling]

I will use a partial bottle if I've had it a couple months for my own bike. If it has seen a winter, it gets tossed.
But if working on a friend's, new every time.

Why? I'm curious. My bike is full of it for a winter and I don't flush it out.

   cling

[sfmichael]

it's probably okay but brake fluid is cheap

[harley_cruiser]

Like stated dot 5 is not hydrophobic, so does not absorbs water, but does absorb some air And makes it harder to bleed. If it was 3,4 or 5.1 I would toss it, but since it is silicone, send it to me and I will use it.
And when you buy new make sure it's genuine Harley dot5. 

Opps,  got it backward, dot 5 is hydrophobic. Thanks sfmichel for the pm.

[Hossamania]

I will use a partial bottle if I've had it a couple months for my own bike. If it has seen a winter, it gets tossed.
But if working on a friend's, new every time.

Why? I'm curious. My bike is full of it for a winter and I don't flush it out.

   cling

Right, so I don't need to add more questionable fluid to an already compromised system. Maybe waste of a little money, but I've made worse decisions before.
And I do try to flush and replace every two years.

[PoorUB]

I would toss it too. I try bleed the brakes at least every two years, sometimes once a year and I buy a fresh bottle every time. Brake fluid is cheap, a lot less money that calipers and master cylinders or ABS modules.