[TR] Converting from DOT3 to DOT5 hydraulic fluid in my TR4A

[dave]

There are many misconceptions, and downright incorrect opinions on this.

First of all, DOT 3/4 is hygroscopic (please note that hydroscopic is
totally incorrect; it refers to a hydroscope, something used to looking at
things underwater).  

Which means it absorbs water.  Which means it must be flushed on a regular
basis.

The only reason to use DOT 3/4 is if you are racing (DOT 5 has a much lower
boiling point) or if you have anti lock brakes.  That's it.  Or, you really
like bleeding your brake and clutch systems.

If you do the research, and look at FACTS, not opinions, old wives
(mechanics) tales, and general misinformation, DOT 5 is superior because it
doesn't eat paint and doesn't absorb water so its much less maintenance.

Those that claim DOT 5 will "trap" water and cause rust are misinformed.  IF
you do the research, which I have done extensively, you will learn that
because bleeding removes all moisture from the system, DOT 5 systems are far
LESS likely to rust than DOT 3/4.

DOT 5 does not eat paint when you spill it or when the hydraulics fail.

People who claim that DOT 5 is bad for rubber and seals are again,
misinformed and incorrect.

If your system failed after installing DOT 5, one of two things happened.
It was about to fail, or you did not flush the system.  DOT 3/4 when mixed
with DOT 5 creates sludge, a very bad thing in the brake system.  You need
to at minimum blow out the system if not flush with alcohol.  To the lister
who claimed his brake system leaked "because of DOT 5" that is impossible.
DOT 5 is silicone, which is actually good for rubber and seals.  If you
experienced failure after switching to DOT 5 the system was about to go
anyway or you did not adequately flush the system or it was user error.  NOT
DOT 5.  

Please, folks, do the research.  Don't rely on hearsay or "old mechanics
tales."  I have extensively researched this issue because there is SO MUCH
misinformation out there.

On a personal note I have converted numerous cars to DOT 5 with nary a
problem.