DoT 4 shelf life

[AberdeenAngus]

Water will make no difference when cold, it will only become apparent when it reaches boiling point (higher than 100deg. C because it will be under pressure) and becomes vapour, which is compressible.

Indeed. If you could keep the temperature well below 100 degrees C, you could completely fill the brakes with water and they would work just fine.
The only reason for using oil is because of the heat that brakes generate.
We often use water based hydraulic systems on subsea kit to be kind to the dolphins.

 

[Stevie4scoops]

I try to buy as little brake fluid as possible, my local recycling centres won't take it

I've put mine in my old motor oil

 

[JJH]

Question. If brake fluid soakes up moisture from the atmosphere could you just have an open container in a room to act as a dehumidifier? JJH

 

[Delboy777]

Question. If brake fluid soakes up moisture from the atmosphere could you just have an open container in a room to act as a dehumidifier? JJH

Would need to be a hell of a container im thinking.

 

[JJH]

Would need to be a hell of a container im thinking.

I won’t be doing it. JJH

 

[JJH]

It just reminds me of a sales pitch that water softener sellers use. If you don’t install one of our systems your central heating will become blocked with lime. Why says I? Because they say. An indirect system uses the same water for years and years. How much lime is contained in that? Now go and take a running jump and come back with a better pitch. Oh yes I already have one installed but I can’t resist. JJH

 

[CPJS]

It just reminds me of a sales pitch that water softener sellers use. If you don’t install one of our systems your central heating will become blocked with lime. Why says I? Because they say. An indirect system uses the same water for years and years. How much lime is contained in that? Now go and take a running jump and come back with a better pitch. Oh yes I already have one installed but I can’t resist. JJH

You must not put softened water into a heating system anyway, sodium has a fun time with iron and aluminium. you should put an unsoftened supply for the heating fill and drinking water.
Either the salesman knows this and is lying, or he does not know and is useless. NEVER trust any salesperson and if you do, doubt them.