Brake Fluid Shelf Life

I was recently gifted a Branick G300 Brake Bleeder that is in need of repairs. My plan is to repair the unit and keep it for home use.

At home, I probably do 1 brake fluid flushes per month, max. Due to the design of the Branick Brake Bleeder, you need to load at least 2 quarts of fluid at a time since the bleeder needs to be "bled" before it is usable. In other words, it is not feasible to load the brake bleeder before each use due to the amount of fluid that gets wasted.

The Branick unit has a built-in rubber diaphragm that seals off the fluid chamber from air exposure. Since the unit is somewhat "sealed," how long can I safely store brake fluid in this unit? I plan to only use DOT3 in this bleeder.
If it is truly sealed, the reservoir is made of metal, kept in relatively normal temperature conditions, and it is charged clean and moisture free, indefinitely.

It should be the same as if it were in a bottle. If the seal is imperfect and allows air to come and go along with moisture, then it would depend greatly on storage conditions.


Staff member
New Jersey
The only real way to tell is moisture content.

I found two bottles of Honda BF in my basement, that I had forgotten about. They are both severely sucked inward. Not entirely sure what that means...

I started NOT filling my motive bleeder, just the reservoir. Keeps the tubing and everything clean, and no chance of wet fluid mixing in next time. If your use is sporadic, it may not be the best option to keep.