2 1/2 Year Old Brake Fluid

[George7941]

I have some sealed unopened litre bottles of brake fluid that have been stored inside my house for 2 1/2 years.

The only concern I have is that the bottles are plastic. and perhaps some moisture has migrated through the plastic into the fluid. If the bottles were glass I would not have any concerns at all about using it..

Safe to use the fluid?

 

[Rand]

How Long Does Brake Fluid Last? In ideal conditions, an unopened bottle of brake fluid lasts about two years. It's best to use a new bottle of brake fluid every time you need it because the fluid attracts moisture as soon as it is opened.

 

[fantastic]

Might as well step up to DOT 4 too while your buying some new fluid.

 

[George7941]

My truck only calls for DOT3 and I do not drive aggressively, so I will stay with DOT3.

 

[slacktide_bitog]

For future reference, Bosch ESI6 comes in a metal can and is a fair price

 

[fantastic]

My truck only calls for DOT3 and I do not drive aggressively, so I will stay with DOT3.

Understood, no harm in that.

 

[dubber09]

Just restocked with that Bosch brake fluid
Not touching Bosch oil filters thou

 

[skyactiv]

I would use that brake fluid without worry.

 

[LongTime_Lurker]

The only way to determine your brake fluid’s condition is through testing.

 

[RhondaHonda]

Stored in a climate controlled house, no worries.

 

[George7941]

DMM probes held apart an inch in the fluid indicates about 15 MOhm (and climbing very slowly) resistamce. I don't think this test gives us any useful information.

 

[eljefino]

It's fine.

 

[JWC86]

The only way to determine your brake fluid’s condition is through testing.

Can you elaborate ?

 

[HowAboutThis]

Can you elaborate ?

Use it and see if your brakes fail. I'm joking, brake fluid is cheap. I'd buy new personally. But I think there are test strips you can buy or you could probably send a small amount to a place to check water content.

 

[HowAboutThis]

Can you elaborate ?

Have never used these and don't know if they're reliable, but I've seen shops show people test strips of their brake fluid. Could be half a scam, could be accurate if used correctly. I haven't researched.

https://www.napaonline.com/en/p/BK_8006B?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Tools-Equipment&campaign_id=8553470562&adgroup_id=107047174069&adtype=pla_with_promotion&gclid=Cj0KCQiAkeSsBhDUARIsAK3tiee_wt-BGqBp3Sb974yzOBwP2mQ0ZdMuqBhhUUsWNLtV0-U6AA1SufsaAnpnEALw_wcB&gclsrc=aw.ds&gad_source=1

 

[LongTime_Lurker]

There are also refractometer devices that allow you to measure the moisture content more accurately. Ahoy matey!

 

[72C10]

Personally, I wouldn't worry about using it but brake fluid is cheap enough. If it bothers you I'd replace it.

If it had been opened, I would toss it for sure.

 

[nate379]

I would use that brake fluid without worry.

I've used stuff that was easily 10 years old, had no idea it expired.

Have run plenty of vehicles that had easily 20 yr old fluid. Stuff looked nassty, but stopped fine.

 

[HowAboutThis]

I've used stuff that was easily 10 years old, had no idea it expired.

Have run plenty of vehicles that had easily 20 yr old fluid. Stuff looked nassty, but stopped fine.

The water, if I remember correctly, is mostly an issue because it'll corrode everything and if you're using the brakes hard (i.e. heating them up a lot) the water doesn't compress when it boils and you'll lose the ability to stop. If you live in flat Kansas probably lower risk of overheating than if you live in a hilly or mountainous area. I replace my fluid to avoid having to replace expensive ABS stuff. But that's my personal reason. A friend decades ago asked what I was doing when I was replacing my fluid and I told them. They'd never done it on, at the time, a 9 year old car. So I did it for them. The fluid was extremely black, gritty, etc. That made me realize all that gunk, if not removed, has gotta clog something up.

 

[nate379]

The water, if I remember correctly, is mostly an issue because it'll corrode everything and if you're using the brakes hard (i.e. heating them up a lot) the water doesn't compress when it boils and you'll lose the ability to stop. If you live in flat Kansas probably lower risk of overheating than if you live in a hilly or mountainous area. I replace my fluid to avoid having to replace expensive ABS stuff. But that's my personal reason. A friend decades ago asked what I was doing when I was replacing my fluid and I told them. They'd never done it on, at the time, a 9 year old car. So I did it for them. The fluid was extremely black, gritty, etc. That made me realize all that gunk, if not removed, has gotta clog something up.

Most of my stuff is pre ABS. That only came common in the late 90s.