TheOne

what is the benefit of using dot 5 brake fluid. Dosn't it just have a higher boiling point or something like that? Also, would I feel a big difference using stainless steel brake lines with dot 5 fluid vs. stock lines and dot 4 fluid? Finally, where can I get dot 5 fluid?

SurferX

DOT 5 is silicone-based which I don't think is very compatible with our brake system. But I've never tried it, that's just what the Acura mechanics say so I've never looked further into it. I'd stick with an upgraded glycoether fluid like the ATE, Motul, etc.

nsxtasy

DOT 5 refers to the government standards*, including minimum boiling points (of 500 F dry, 356 F wet).

There are two different kinds of DOT 5 brake fluid. "Normal" DOT 5 is silicone based brake fluid (also known as SBBF). The advantage is that it doesn't absorb water easily. The disadvantage is that it doesn't mix with other brake fluids, and it's not recommended for our cars. These are important because it means that to use it, you would have to flush ALL your brake fluid and you would never be able to use anyone else's to top off. Very inconvenient to say the least.

However, you can also get DOT 5.1 brake fluid. This is non-SBBF so you can mix it with DOT 3 and DOT 4 if you have to. But it meets those higher DOT 5 boiling point standards.

Basically, you can judge brake fluid by its boiling points. The higher the boiling temperature, the more resistant the brake fluid is to boiling - dry boiling temp when it's straight out of the bottle, wet boiling temp after it's been in the car a while and absorbed moisture over time.

Here are the dry and wet boiling points for many of the most popular brake fluids:

ARRANGED BY DRY BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:527F -- WET:302F --- AP RACING 551
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:590F -- WET:518F --- CASTROL SRF
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610
DRY:620F -- WET:425F --- COBALT SUPER XRF

ARRANGED BY WET BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:527F -- WET:302F --- AP RACING 551
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610
DRY:620F -- WET:425F --- COBALT SUPER XRF
DRY:590F -- WET:518F --- CASTROL SRF

* NOTE: If you want to read the government standards for brake fluids, and find out what they say, you can do so here.

tjtruong

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nsxtasy &raquo;</TD></TR><TR><TD CLASS="quote">DOT 5 refers to the government standards*, including minimum boiling points (of 500 F dry, 356 F wet).

There are two different kinds of DOT 5 brake fluid. "Normal" DOT 5 is silicone based brake fluid (also known as SBBF). The advantage is that it doesn't absorb water easily. The disadvantage is that it doesn't mix with other brake fluids, and it's not recommended for our cars. These are important because it means that to use it, you would have to flush ALL your brake fluid and you would never be able to use anyone else's to top off. Very inconvenient to say the least.

However, you can also get DOT 5.1 brake fluid. This is non-SBBF so you can mix it with DOT 3 and DOT 4 if you have to. But it meets those higher DOT 5 boiling point standards.

Basically, you can judge brake fluid by its boiling points. The higher the boiling temperature, the more resistant the brake fluid is to boiling - dry boiling temp when it's straight out of the bottle, wet boiling temp after it's been in the car a while and absorbed moisture over time.

Here are the dry and wet boiling points for many of the most popular brake fluids:

ARRANGED BY DRY BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:527F -- WET:302F --- AP RACING 551
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:590F -- WET:518F --- CASTROL SRF
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610
DRY:620F -- WET:425F --- COBALT SUPER XRF

ARRANGED BY WET BOILING POINT:

DRY:401F -- WET:284F --- DOT3 MINIMUM
DRY:527F -- WET:302F --- AP RACING 551
DRY:446F -- WET:311F --- DOT4 MINIMUM
DRY:502F -- WET:343F --- VALVOLINE SYNPOWER
DRY:500F -- WET:356F --- DOT5 MINIMUM
DRY:509F -- WET:365F --- MOTUL 5.1
DRY:536F -- WET:392F --- ATE SUPERBLUE/TYP200
DRY:590F -- WET:410F --- AP RACING 600
DRY:593F -- WET:420F --- MOTUL RBF600
DRY:610F -- WET:421F --- NEO-SYNTHETIC SUPER DOT 610
DRY:620F -- WET:425F --- COBALT SUPER XRF
DRY:590F -- WET:518F --- CASTROL SRF

* NOTE: If you want to read the government standards for brake fluids, and find out what they say, you can do so here.
</TD></TR></TABLE>

he basically covered it all. Great info