Copied directly from your reference.April 17 2017 at 7:04 AM
|kleandan (Login kleandan)|
Response to Old oil is fine but not opened brake fluid.
"Because of their affinity for atmospheric moisture, hygroscopic materials might require storage in sealed containers."
This suggests storage in a properly sealed container will control the hygroscopic effect.
If the sealed bottle will not control the hygroscopic effect the fluid will be bad regardless of it being open, closed, new or old.
- Yep! - Bob on Apr 17, 2017, 2:05 PM