is dot 5.1 brake fluid bad for the street?

[Jingers]

If so what are the reasons?

[vtml]

You have to bleed them more often than the traditional DOT 4 fluids for a start.

[tinkerbell]

really?

i thought that was DOT 5?

the downside to DOT 5.1 = price...

[vtml]

In my experience anyway Tinker. I am using DOT 5.1, last time I bleed it (it was a good bleed as well as I do it myself with my own method ) was only 15,000km ago, and I drive like a granny and haven't tracked my car for almost 1.5 years, my pedals are now a bit soft and I just know there's definitely some air bubbles in my lines.

[fueltank]

Rbf600 = Dot4
and it seems good enough for track/street.

[no_torq]

i thought that dot 5 was not suitable for street use. they use it in tractors and alike. It contains silicone. It compresses more and will give a spongey feel .Dot 5.1 is suitable for street use. I just use castrol super dot 4. which is rated at dot 5.1 specs.

[tinkerbell]

my pedals are now a bit soft and I just know there's definitely some air bubbles in my lines.

well, if there in indeed air bubbles in your lines then you have an air leak in you hydraulic system...

air does not materialise in brake fluid by magic...

and yes, i have read about your "method" of brake bleeding... and thought: "well, if you are happy, then i won't comment"

but it sounds like you might be unfairly and incorrectly blaming the fluid for your soft pedal...

[Wlee2]

I never tried Dot 5 before..

but Dot 5.1 i always though required less bleeding..

i thought it was the temperature rating and price was the difference between Dot 5.1 and dot 4..

I tried the Castrol Super Dot 4.. its quite nice and actually affordable =P
trying out penrite Sins Plus i think its a 5.1 it says rated at 600 degrees ( i assume Fahrenheit?)

Cheaper than Motul.. cant really give much comparison.. but i thought the Penrite had a really firm feel.. and still very firm..

and what Tink said.. air doesnt materialise from nothingness..

[Jingers]

funnily the dot 5.1 is cheaper? motul 5.1 is $13.50 as compared to rb600.

i read up on the 5.1 and the 5.1 is supposed to be a hybride dot 5 fluid and the main factor is that it is non silicon and will mix well with other dot 3-4-5 fluid for those not doing a completly squeeky clean flush

5.1 is definitly not silicon as a silicon fluid requires the whole braking systems to be taking apart and cleaned out.

Thanks to a link ed gave me i think its partly becuase dot 5 does not absorb air and therefor create airpockets which can corrode the braking system. Where as the dot 3-4 absorbs the air

[Wlee2]

funnily the dot 5.1 is cheaper? motul 5.1 is $13.50 as compared to rb600.

i read up on the 5.1 and the 5.1 is supposed to be a hybride dot 5 fluid and the main factor is that it is non silicon and will mix well with other dot 3-4-5 fluid for those not doing a completly squeeky clean flush

5.1 is definitly not silicon as a silicon fluid requires the whole braking systems to be taking apart and cleaned out.

Thanks to a link ed gave me i think its partly becuase dot 5 does not absorb air and therefor create airpockets which can corrode the braking system. Where as the dot 3-4 absorbs the air

I always thought it was absorbing moisture in the air more than actual air itself..

but could be wrong on that one i only heard it not read it =P

[tinkerbell]

RBF 600 has better wet boiling point though...

http://www.stoptech.com/tech_info/wp...fluid_1a.shtml

http://www.stoptech.com/tech_info/wp...mparison.shtml

[twmwong]

You have to bleed them more often than the traditional DOT 4 fluids for a start.

Oh really...I haven't bleed mine for almost 3 years and still works fine & hard

[G_Vtec]

it really comes down to the sort of driving you are looking at...

if you intent to keep the car on the road, a good flush every few years is sufficient enough.

if you intent to track the car, do a complete flush on the eve of the track day but even then, you would need braided lines, slotted rotors and a set of good pads to fully compliment the flush. I know i used to flush my fluid with RBF600 and it held up very well on QR and Darlington

p.s. - braking on public roads is very different to braking on the track

[tinkerbell]

Oh really...I haven't bleed mine for almost 3 years and still works fine & hard

ssshhhhssshhh!

maybe it is because you don't brake hard enough!

[Wlee2]

ssshhhhssshhh!

maybe it is because we don't brake hard enough

that said, i am going to bleed mine for the first time in 10 months... before eastern creek SS on the 22nd...

brake fade at eastern creek turn 2 is not fun

What fluid are you running tinks?