Shelf life for open brake fluid
 

Once you crack the seal on brake fluid is it safe to use again after its been sitting for a few months ?

I am looking to bleed my brakes tomorrow and would like to finish off what's left of my castrol SRF plus open another new bottle that I would plan on using again next time I bleed the brakes

any issues with that plan ??

Thanks

Probably fine. If you worried about it, pour it into your super clean jar, or measuring cup and look at it. If it looks like vegetable oil, cool. Looks like motor oil, no.

https://blog.amsoil.com/dot-3-and-do...he-difference/

Mentions dot3 can absorb 2% per year, the more moisture in the brake fluid the lower the boiling point will be. I won't use old bottles myself, especially if it's going on track.

Hmm the old fluid is not even a year old but I guess some moisture might have got In. I do keep it inside my house rather than outside in a garage if that matters lol

Thanks for the link

Okay I used some of the new bottle mixed with the rest of the old bottle. Job done and the brakes feel great. We will see how they hold up long term

Plastic wrap over top of the opening and then putting the cap on top of that might be an effective moisture barrier.

Put the un-used bottle in your drawer

next to your panties.

instructions unclear, everything is in a bunch now.

If the cap is tight it can only absorb what moisture is inside the bottle. 2 months 2 years does not make any difference. You will be fine. If you store it outside with the cap off I would not use it.

I have a bottle of Stoptech SRF660 fluid that was opened ~4 years ago. Just tested it a few days ago with test strips. The strip barely showed any contamination at all. It probably is at least 98% good. Bottle was sealed with just the regular cap and stored in my garage.