On 18/06/2020 08:32, John B. wrote:
On Wed, 17 Jun 2020 23:07:14 -0700 (PDT), wrote:

On Thursday, June 18, 2020 at 6:48:38 AM UTC+2, John B. wrote:
Someone cautioned that DOT brake fluid, in bicycle disk brakes, should
be changed annually.
Is this correct? A requirement of the disk makers? Or ?
--
cheers,

John B.

Never heard of that requirement. In my car is is changed every 2 years.

Lou

Somebody here, talking about bicycle disk brakes mentioned that DOT
liquid must be changed annually while mineral oil did not require
this.

As the DOT brake oil in my pickup truck has been there for probably 20
years without being changed I asked the question.

Reading, after I posted up there--^ DOT 3,4 and 5.1 are hygroscopic
polyputtheketteon, DOT 5 is silicone and isn't.

Soo...hygroscopic ones need replacing, silicone ones last a lot longer.

So if it has silicone it will probably be ok, the issue is moisture
pools at the bottom of the system potentially causing rot.