Rev up your engines, today I'm going to be talking about the best
brake fluid for your car and why it's so, now brake fluid makes your brakes stop so,
here's a little history lesson to show you what you should use by learning from history,
now in 1924, hydraulic brakes were first used on mass produced
cars, and yes that was before my time,
they were alcohol or caster oil based, and they worked ok for those old cars,
but there boiling point was too low for any modern cars,
in modern cars, rarely do your braking system, the rotors and stuff,
get above 400 degrees fahrenheit, but the boiling point of this old stuff was
374 degrees fahrenheit, so it could make it boil,
and guess what, you don't want your brake fluid boiling,
is worse for your brake fluid to be boiling than even your engine water,
because if they boil, the brakes will stop working, they will just fade away,
the early system were called DOT 2, you can't really buy that stuff anymore,
now even when I was a young mechanic in the 60's,
almost all the systems used the more modern stuff that's called DOT 3,
it means department of transportation, it's a rating system,
but back then we just called it brake fluid, no one was even thinking about that stuff,
we just poured it in and used it and didn't think about what types you need,
the DOT 3 is a glycol ethers based brake fluid, and it's boiling point is 401 degrees fahrenheit,
and since the rotors rarely get above 400 degrees fahrenheit,
that's good but still 400 or 401 degrees, if you drive really hard, you might think
about something else, like DOT 4 which is a glycol borate mix,
and it can go to 446 degrees fahrenheit, so your never really going to have to worry
about boiling the stuff out, now many modern cars now come with DOT 4 brake
fluid, it's really top of the line for mass produced
cars, now there is DOT 5 fluid, which is a silicone
based fluid, but you can't use that in most modern cars
with ABS because it messes with the ABS system, the DOT 5 main use is in military vehicles
here in the United States, because it's not based like the other ones
are, it's a silicone based thing, so it does not
absorb water moisture, so you never have to worry about water moisture
contaminating your system, so the military loves it because if they're
in really cold places, they don't have to worry about water getting
in the system and it freezing and then not working when it's really cold,
but you really can't use the DOT 5 in many car,
the silicone ones don't mix with the other type ones that are based on different chemistry,
and like I said it can destroy the ABS system, somehow it foams up or something and it just
won't work right, so you can't use DOT 5 on any car your driving
on the street, of course the military loves DOT 5 because
since it doesn't absorb water, they never need to change the stuff,
they can leave it in there pretty much an infinite amount of time and they're not going
to have any problems from the system's fluid going bad,
but scientists being what they are, they've invented now DOT 5.1,
it has the same boiling temperature as the silicone based 5, which is 500 degrees fahrenheit,
but being a glycol borate mixture, it can be used with any of the other systems,
you can put DOT 5.1 in DOT 4 or DOT 3, you don't have to flush anything out,
it can work perfectly fine with any of them, where the DOT 5 you can't mix with anything
except DOT 5, so the DOT 5.1 is really the best brake fluid
you can buy for cars you drive on the street, you might not necessarily need that much if
your not braking like a maniac, the DOT 4 will work perfectly fine for most people,
so really for conventional driving, the DOT 4 fluids are perfectly fine to use,
but if you want the absolute best with the highest boiling point, you get DOT 5.1
and if your thinking about switching your system over to 5.1,
the great thing is, say you want to flush it out and put the new stuff in,
you don't have to get every little drop of the old stuff out, because they mix perfectly
fine, if you had a tiny bit left, maybe instead
of having a boiling point of 500 degree fahrenheit, maybe it would be like 460 or 470 but still
that's way higher than what you need, and this being mechanic monday,
I'm giving away a bottle of the DOT 5.1, even though it's super expensive, and remember
to get a chance to win, just post a clean non offensive comment on the YouTube comments
below, and a winner will be randomly chosen by a
computer to get a bottle of this stuff, so if you never want to miss another one of
my new car repair videos, remember to ring that bell!