Brake fluid

How long can you keep an opened new can of brake fluid for ?

Reply to
munki
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How long can you keep an opened new can of brake fluid for ?

Reply to
munki

How long can you keep an opened new can of brake fluid for ?

Reply to
munki

At 10:37 it's OK At 10:38 it's gone orf....

Reply to
Adrian C

Even if its in the sealed bottle it came in ?

Reply to
munki

tightly sealed and indoors, use it within a year or so.

Reply to
Mrcheerful

Top man!

Reply to
munki

But if you've opened it, its no longer sealed.

Reply to
Conor

I'll bite and guess he mean't meant a screwed up bottle it came in.

Normally once its been opened use it or get rid it. And never reuse old brake fluid. (to op)

Reply to
Peter smith

Keep asking until you get the answer you want ;)

If you don't use it all in one go, get rid of it. It's not expensive and you don't want to be using brake fluid in a years time that's already been exposed to the atmosphere and absorbed water, which will reduce it's effectiveness.

The whole reason brake fluid needs changing is because it's hydroscopic.

Reply to
Davey

Given the master cylinder is open to the air via a vent hole, how do you come to this conclusion? Unless you mean stored with the top off.

Indeed.

Life wise I'd say use before the same sort of time the makers spec for a fluid change.

Reply to
Dave Plowman (News)

I was told by a mechanic that brake fluid is hydroscopic and once opened use what you need and disregard the rest.

Speaking of which mines been brewing for about 2 and a half years so due a change. I've got an gunson eezibleed somewhere that made this job easy last time I did it.

Reply to
Peter smith

Peter smith gurgled happily, sounding much like they were saying:

Correct.

As Dave says - when it's in the car, it's open to the atmosphere through the breather hole in the master cylinder cap. It has to be, else it couldn't compensate for the rise and fall in level that occurs naturally as pads wear and pistons extend further.

So "bin immediately" is a bit of overkill. OTOH, if it's been sitting in an open bottle absorbing moisture from a damp shed for a couple of years, then goes into the car, it's going to have had four year's worth of absorption by the time it's due for a change.

For a commercial garage where a bottle won't last long on the shelf, I'd have no issues. For a domestic DIYer where an open bottle might last aaaaages, I'd bite the bullet and lob it.

Reply to
Adrian

So if you keep it in a sealed container it's fine. It does however need a proper seal.

Reply to
Duncan Wood

I just do the top up tight and wrap a plastic bag around the whole bottle. Not because I'm penny pinching, but because I know that if I chuck it away, I'm bound to find myself needing it at an awkward moment.

Reply to
Willy Eckerslyke

and the word is hygroscopic.

Reply to
Mrcheerful

Then how do you stop it getting into this condition while in use - and open to the atmosphere? When you seal up the container the amount of water is restricted to what's in the air so enclosed. Not so with a master cylinder.

Reply to
Dave Plowman (News)

Assuming the bottle has a vaguely effective seal, most don't.

Reply to
Duncan Wood

I thought modern stuff (dot 5) wasn't?

Reply to
Blah

Dot 5 isn't it's silicone, but almost nobody uses it , partly for that reason, 5.1 is still a bit hygroscopic, but its wet boiling point is much higher than Dot4s

Reply to
Duncan Wood

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