[British-cars] Castrol LMA Brake Fluid Question

[Randall]

> but have found their synthetic version

No worries, it's the same stuff!  All they did was add "synthetic" to the
label.  

"Synthetic" has become a nearly meaningless marketing term (like "fresh
frozen" fish); by the current definition brake fluid has always been
"synthetic" because it is not refined from petroleum.  (Petroleum can be
used to make glycol, but there is no glycol in petroleum.)  The
manufacturers have figured out that people are willing to pay more for the
"synthetic" label, so they've started sticking it on brake fluid.

> I guess I'll scrounge
> around
> for some other DOT 4 brand.

That _may_ be a bad idea.  Many years ago, I was told and proved to myself
that non-Castrol (and non-DOT 5) brake fluid would eat Girling seals.  For
Triumphs, that has apparently changed and is no longer true for seals made
in the past 25 years or so.  Maybe it's true for all vintage Girling brakes,
but I don't know that.  And somebody somewhere is probably still using seals
made before the change.  (Come to think of it, my front caliper seals are
probably coming up on 25 years old.  I love DOT 5!)

-- Randall