Brake fluid shelf life

[bcgreen]

I understand once a container of Brake fluid is opened it must be discarded because it attracts condensation.
What if the opened container is vacuum sealed?

[Classic 911]

Good question.

Here’s something I found online.

"The standard shelf life of an unopened bottle of brake fluid is 5 years. This means within this time frame the brake fluid will not show signs of degrading or bottle fatigue within its shelf life."


https://blog.*******.com/know-thy-brake-fluid


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[GH85Carrera]

You can buy an inexpensive brake fluid tester from Amazon. If the moisture is still at 0% use it, unless you are about to do a track day.

If you screwed the cap back on, not much moisture will get in there if any.

I replace my 85 911's brake fluid every single spring, for the last 31+ years. Brake fluid is cheap and a full flush keeps things clean and happy. I have never had to do anything to the brake master cylinder even after 193,000 miles. I had the calipers rebuilt only because they were looking bad on the outside and I had PMB rebuild and replate them to look like new.

[EC900]

Interesting debate.
When you buy a liter of BF, there’s no printed Lot number/Date code/Use by on the bottle, the only storage disclaimer is Keep in original container, in a dry location and cap tightly closed.
I never had a fluid flush as part of routine maintenance but only as a brake job.
Never had much concern until there was a recall from Harley Davison over their Dot4 BF formulation that became susceptible to gelling and deposits forming clogging the ABS valving.
All chemical compounds change over time just from sitting. Medicines in particular come to mind…some things you don’t want to shortchange.
I have a BF bottle from 4/2021 thats been opened. If I get a chance I’ll buy a meter and test it and report back here with results.

[PeteKz]

What causes BF to degrade is moisture. Keep it tightly capped and you're okay for a long time (years?). It mostly depends on your local atmospheric conditions.

Hint: Buy BF in the small bottles, so that you don't have a large bottle, that after you open it, has lots of air in it.

[bcgreen]

Originally Posted by PeteKz

What causes BF to degrade is moisture. Keep it tightly capped and you're okay for a long time (years?). It mostly depends on your local atmospheric conditions.

Hint: Buy BF in the small bottles, so that you don't have a large bottle, that after you open it, has lots of air in it.

Vacuum seal after its been opened?

[bcgreen]

Originally Posted by EC900

Interesting debate.
When you buy a liter of BF, there’s no printed Lot number/Date code/Use by on the bottle, the only storage disclaimer is Keep in original container, in a dry location and cap tightly closed.
I never had a fluid flush as part of routine maintenance but only as a brake job.
Never had much concern until there was a recall from Harley Davison over their Dot4 BF formulation that became susceptible to gelling and deposits forming clogging the ABS valving.
All chemical compounds change over time just from sitting. Medicines in particular come to mind…some things you don’t want to shortchange.
I have a BF bottle from 4/2021 thats been opened. If I get a chance I’ll buy a meter and test it and report back here with results.

I would like to hear from your findings.

[KRLocke]

I keep my opened can in a nearly constantly dehumidified room, important for other things in the room. So I'm sure it will be good for years.

What about keeping an open can in the freezer? Low/no humidity.

[PeteKz]

Originally Posted by bcgreen

Vacuum seal after its been opened?

BF comes in plastic bottles now, so you couldn't draw much of a vacuum--the bottle will squish. If you screw on the cap reasonably tight, and turn it upside down, and no BF leaks out, I think that is a good enough seal.

[porsche930dude]

It definately doesnt last forever. I used on a used bottle when I rebuilt my jeep and 4 months later a wheel was locking up because the wheel cyl was so corroded. I dont know how long the bottle was opened but now i know im not using an opened bottle on the porsche

[GH85Carrera]

Brake fluid is pretty cheap compared to brake parts or collision damage due to bad brakes.

I do a through flush every spring, and take to old fluid to our hazardous waste disposal site along with old motor oil and other household stuff.

I will admit on my El Camino daily driver I only change the brake fluid every other year.

[PeteKz]

Originally Posted by GH85Carrera

Brake fluid is pretty cheap compared to brake parts or collision damage due to bad brakes.

I do a through flush every spring, and take to old fluid to our hazardous waste disposal site along with old motor oil and other household stuff.

I will admit on my El Camino daily driver I only change the brake fluid every other year.

"Only" every other year? That's a lot better than 90% of the cars on the road!

[porsche930dude]

Originally Posted by PeteKz

"Only" every other year? That's a lot better than 90% of the cars on the road!

More like 99.99% Probably changes the coolant too

[GH85Carrera]

Originally Posted by porsche930dude

More like 99.99% Probably changes the coolant too

Yep, I change the coolant in the El Camino every other year as well. When I look in the radiator, there is no speck of corrosion or crud.

I have never changed the antifreeze in the 911 as I can't find the water pump or radiator!