Well, I've done a little research on this before, so I know the basics about the different numbers, qualities of the fluid, and so on. Obviously the main things you need to think about are the DOT number, if the fluid is compressable, and how slowly or quickly it will suck up moisture in the brake system. Obviously you want your fluid to suck up some moisture, but not to the point that it saturates itself within 6 months. If you're driving a street car, you aren't going to want a fluid that needs to be compressed to start working, meaning you need to pump the pedal once to get the brakes to function correctly.

I know the DOT 3 and DOT 4 can be run in any hydraulic brake system, usually the DOT 4 being a little more expensive than the 3. But, DOT 4 is much higher quality, seeing as how it does not suck up water as quickly and usually has higher boiling points and a longer shelf life. DOT 5 and DOT 5.1 are what you need to steer away from. DOT 5 is silicone based and is very compressable, not to mention it does not suck up moisture very easily. Usually it is used in show cars where if it leaks or is spilled it will not damage paint. I believe DOT 5.1 follows the same basics.

So, while doing my research I came across a few popular choices. First off, Ford Heavy Duty DOT 3 brake fluid. This fluid is very cheap, has high boiling points, and can be pretty easily found. Also, it's not compressable, but will soak up moisture much more quickly since it's a DOT 3 fluid. The next choice I found was Castrol GTLMA (low moisture absorbtion). The boiling points aren't quite has high as the Ford fluid, but will last much longer and is also pretty cheap to buy and can be found eaily too. The third choice I found was ATE Super Blue or Super Gold (they are the same fluid, just different colors). This fluid has extremely high boiling points, is compressable, a little more pricey, and most of the time needs to be ordered online. It doesn't suck up moisture as well as the Castrol or Ford fluids, so it's mostly used in race vehicles where brakes are bled more often. There's a few others too, but their price and compressability issues make them not that useful for a street car.

For my application (daily driver) I was planning on going with the Castrol GTLMA since it will be able to go longer without having to bleed it out and fill with new and also has high enough boiling points that I won't ever have to worry about boiling it, even if I drive the car hard. So, what are your guy's suggestions?

 

Nobody has any opinions on this?

 

Dude, it's a daily driver and you're worrying about boiling the brake fluid. Think about that for a second.

 

While I respect your service dedication, I have to agree. Any mainstream DOT 3, change on schedule. Heck, my local shop would not even flush my 300,000+ Accord. The full stroke in the master cylinder that results from putting the brake pedal to the floor causes internal parts thru a range that is not used normally used. In an older car they say, it can cause damage. Who knows.

 

Well, I wanted to go with a the best fluid I could, but didn't want something that was going to be compressible or not suck up moisture or suck it up too fast. It seems to be a lot of the race fluids are compressible or don't suck up moisture as quickly. The Ford DOT 3 is nice ****, but it won't last as long as the Castrol will. Also, what's the deal with synthetic brake fluid compared to regular brake fluid?