Dot 5.1 here...Ate Blue. It's good stuff and pretty cheap but a little hard to come by. But I road race my car, so its prolly overkill for you. I would recommend the valvoline syn power stuff. Its got a 500 deg. dry boiling point and its very cheap and available at pretty much any auto parts store which sells valvoline stuff (which is pretty mech all of them).
Thanks for the input guys. I was told once that certain brake fluid would eat through your brake lines if you didn't have the stainless steel ones. Probably someone trying to brag about how much better the SS lines are since they had them
- Justin
All DOT brake fluids are backwards compatible (up to dot 4)...so you can use dot 3,4 and most 5.1's. DOT 5 is silicone and that is bad for various reasons..wont get into that. If you get a dot 5.1 make sure you check to make sure they are compatible with dot 3/4 fluids. After DOT 4 is the gray area (in terms of backwards compatibility) so if you dont want to worry about it...stick with DOT 4 or 3. Although the valvoline syn power stuff I mentioned is compatible and quite good.
On a car that doesn't see the roadcourse, or heavy braking for 30+ minutes at a time, there's no point in running a DOT 4-5+ fluid. It doesn't magically make you brake better, and in most cases will hurt you more. The DOT 4 and 5 fluids attract moisture a lot more than a DOT 3, so it ends up with a lower boiling temp than a DOT 3.
Cliffs: Stick with DOT 3 unless you have a roadrace car. If you have DOT 4-5, bleed it regularly.
DOT 3 and 4 actually have pretty equal moisture absorption properties. But DOT 4's have a higher wet boiling point which is a plus. Also, DOT 5.1's (the gray area) CAN be much less hydroscopic than the dot 3's and 4's and have a higher wet boiling point than both dot 3 and 4. For example the Ate Blue I use..I buy it by the case and use it in my dads cavalier, moms windstar, bros cavalier, and obviously the stang. Because it lasts more than twice as long as the dot 3/4 stuff because it absorbs much less moisture than both. And when flushing an entire brake system the Ate stuff costs $10-$15 more than the cheapo dot 3 stuff. Its recommended that you flush your brake fluid every year...so would you spend an extra $10-15 to keep from flushing brakes every year? I know I would. -Robin
DOT 5 , DOT 5 will eat some rubber seals if the breaking system is not made for it. I know for a fact in mustangs you can run 3 or 4. The only reaon i know this is because i use to work at a motor cycle shop, sold a guy DOT5 for an older motorcycle and what do you know the shop had to pay to replace his entire breaking system. But this is just a caution, i would do somme more reaserch cause im not 100% sure on the mustang
Dot 5 and 5.1 are diff. Dot 5 is silicone based and 5.1 is glycol based like 3 & 4. Yea dont use dot 5 its very bad. If mixed with glycol based stuff (dot 3, 4, 5.1) it turns into a sludge of almost peanut butter consistency....very, very, bad for your braking system.