On 2/19/2017 9:31 AM, Brewster wrote:

This was a few years ago, but I remember the old standby DOT 3 fluid
(maybe DOT 4?) was considered permanent and was not prone to being
hydroscopic. The newer fluids, synthetic (DOT 5 ?) was very prone to
absorbing moisture and had to be changed regularly. Given the much
higher cost and no real advantage for non-performance driving. the idea
of "upgrading" soon left my thoughts.
I had a number of vehicles from the 60's and 70's, all with non
stainless lines. Never any problems (though these were all southwest
vehicles).

Same here, except my vehicles were in the rust belt, and started in the
50's rather than the 60's. Actually my first car was a '49 Dodge Truck.
Everything in Cars from the '50s rusted except the frame and break lines.

Even if newer fluid is more hygroscopic, I still think the rust is
coming from the outside, not the inside of the lines.

IF the newer fluid was causing brake line failure, you might think Big
Brother would be all over it, like they got over freon in air
conditioners, or VW for fudging the MPG stats.

--
Jack
Add Life to your Days not Days to your Life.
http://jbstein.com