Emery S wrote;
> Whatever you decide to use, add the periodic flushing and refilling to
your
> list of preventative maintenance items and you should eliminate future
> problems caused by fluids.
I think this is the key- there are no brake fluids availible you can put in
and 'forget about' indefinitely. They all have advantages and disadvanages,
but regular GM Spec fluid or its equivalent is perfectly good. Brake systems
do have some aspiration naturally and will eventually pick up moisture. This
is normal and cant be prevented. The important part is changing fluid at
regular intervals before this water reaches a volume that it can deteriorate
brake system parts or cause low enough boiling points that the fluid boils
and can vapour lock your system and lose one or both circuits. This is a
very hopeless feeling when it happens...
Annual fluid changes are certainly enough for even the dampest environments,
but even in very dry areas once every 3-4 years is not too often. I do my
own vehicles annually here in Vancouver which is much like Seattle generally
for normal weather. No magic brake fluid will extend these general intervals
very far. The one happy thought you may console yourself with to offset the
cost and inconvenience of frequent brake flushings is the big parts will
last nearly indefinitely if its done regularily. Brake pipes and hoses need
fairly regular inspection in any event, its well worth getting under there
and looking at them, and replacing 'rubber' parts at regular intervals and
steel lines as well.
>From my own perspective I feel the silicone fluids are unsuitable for most
people. If I owned a collector car that sat around all the time in a
controlled environment and only occasionally ventured out for some very
gentle driving, I'd consider it, but this is far from the brief for the
typical GMC. None of the Automobile Manufacturers approve/recommend silicone
fluids at the present time to my knowledge, citing a variety of reasons,
from ABS incompatibility to seal deterioration among other things.
FWIW, I'd use conventional fluids (or the high boiling point versions) and
just make a point of flushing them out every once in a while, certainly
every couple years (or less) in most environments, regardless of
mileage/service time.
Brent Covey
Vancouver BC
