CHF 11s shelf life?

[audioslave]

In the past, I was in the habit of not storing open containers of traditional brake/PS fluids for extended periods of time. I just purchased my first liter of Pentosin for a top-off and while I believe moisture absorption for something like a synthetic PS fluid is a non-issue I wanted to confirm.

[dparm]

PS fluid is hygroscopic, but since it isn't seeing the crazy temperature swings of brake fluid, the water won't drastically alter the operating characteristics.

[kenwelch]

Originally Posted by dparm

PS fluid is hygroscopic, but since it isn't seeing the crazy temperature swings of brake fluid, the water won't drastically alter the operating characteristics.

If it was a problem BMW would not have the open type vent on the power steering cap. Also it would not be listed as "life-time" on the Pentosin tech sheet.

"Pentosin CHF 11S is a synthetic high performance
hydraulic fluid for life-time application in modern vehicle
aggregates."

[dparm]

BMW calls many fluids lifetime. It's really their way of dodging some of the free maintenance costs. Water contamination is not something I associate with power steering fluid, but contamination with other things is.

[Keynesallacy]

The bearings were also placed in connecting rods, torqued, and clearances properly measured. The dimensions listed above are actual dimensions and not approximated based on bearing thickness differences.

[audioslave]

I don't know about "lifetime fill" at the rate our fluid tends to boil over (kidding).

Seriously, thanks all for the input! Glad I don't have to toss the $$ fluid I have left.