[BlackWorksInc]

Curiously enough, there hasn't been any questions raised about switching to a better grade of brake fluid on the forums (or at least my search-fu is not good enough when using "DOT4 vs. DOT5/ DOT5.1 / DOT 4 & DOT 5.1 ) and I am curious if anyone is running them?

I had thought about switching to a DOT4 when I flush my brake fluid again and debated on whether or not I wanted to use DOT5 (my only experience with DOT5 is that it is often used in race vehicles & motorcycles,) but there are a couple issues with DOT5. First of all is that while DOT5 does not rust out the system (it is not hydroscopic like DOT 3,4, & 5.1) due to its silicone base; it does require all the rubber lines, gaskets, and non-metallic components be replace when switching from DOT 3 or 4. The second issue is that due to its viscosity differences, it is not suitible for ABS (according to what I have found about it on Google at least.)

I came across a "DOT5.1" which is a polyethylene glycol based fluid like DOT3 & DOT4, but I have no real information other than it is used in fleet, HD, and racing applications. Anyone have any experience with this fluid?

[BlackWorksInc]

No one has anything on this stuff?

And no don't say "it gives you surround sound!" one of the jokers on T120 already tried that! LoL

[Atlanta_man]

and they say "super DOT4" is the same as DOT 5.1

[ebg18t]

I have never used DOT 5 in any of my vehicles due to possible issues with the silicone latching into normal material residue (from degradation) in the system. When this happens it can create a gel/sludge in the system readying the effectivness of the system. Introducing DOT5 fluid into older brake system only exasperates this issue.

If you are looking for a hardier fluid, or a fluid that doesn't require bleeding as often DOT5.1 isn't always the answer either. My other car is track prepped and I did use DOT5.1 for some time. It handled the heat well, but it required bleeding every year at a min as it captured a ton of water from the heat cycling.

Now I am back on DOT4 fluid and bleed it annually. My 4Runner gets bleed every other year. I use the ATe Type 200, it's cost effective and has a high dry & reasonable wet boiling point.

[chayos00]

Originally Posted by ebg18t

I have never used DOT 5 in any of my vehicles due to possible issues with the silicone latching into normal material residue (from degradation) in the system. When this happens it can create a gel/sludge in the system readying the effectivness of the system. Introducing DOT5 fluid into older brake system only exasperates this issue.

If you are looking for a hardier fluid, or a fluid that doesn't require bleeding as often DOT5.1 isn't always the answer either. My other car is track prepped and I did use DOT5.1 for some time. It handled the heat well, but it required bleeding every year at a min as it captured a ton of water from the heat cycling.

Now I am back on DOT4 fluid and bleed it annually. My 4Runner gets bleed every other year. I use the ATe Type 200, it's cost effective and has a high dry & reasonable wet boiling point.

That is good feedback about the DOT5.1, when I did my wife's TL at the end of last year, I was looking into the 5.1 but due to the cost of it and trying to find it locally, I just went with DOT4. Glad I didn't use the 5.1 now.

[nevada]

unless you're really working the brakes hard, DOT3 is fine.

the only gain with dot4 is a higher boiling point, but if you aren't boiling the dot3, you gain nothing by switching.

[Gdunc]

Originally Posted by BlackWorksInc

Curiously enough, there hasn't been any questions raised about switching to a better grade of brake fluid on the forums (or at least my search-fu is not good enough when using "DOT4 vs. DOT5/ DOT5.1 / DOT 4 & DOT 5.1 ) and I am curious if anyone is running them?

I had thought about switching to a DOT4 when I flush my brake fluid again and debated on whether or not I wanted to use DOT5 (my only experience with DOT5 is that it is often used in race vehicles & motorcycles,) but there are a couple issues with DOT5. First of all is that while DOT5 does not rust out the system (it is not hydroscopic like DOT 3,4, & 5.1) due to its silicone base; it does require all the rubber lines, gaskets, and non-metallic components be replace when switching from DOT 3 or 4. The second issue is that due to its viscosity differences, it is not suitible for ABS (according to what I have found about it on Google at least.)

I came across a "DOT5.1" which is a polyethylene glycol based fluid like DOT3 & DOT4, but I have no real information other than it is used in fleet, HD, and racing applications. Anyone have any experience with this fluid?

I bought Dot 4 today. I think it sweats less and for traction control, abs systems. Better for heavy vehicle I think