Best Brake Fluid DOT3

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Supertech is probably made by one of the major suppliers, and because every DOT3 brake fluid must meet the same standards their isn't going to be a big different between them, I'd trust it.
 
Use it, its fine. Brake fluid is brake fluid, they're all synthetic and meet the requirements listed on the bottle. Hard to tell the difference.
 
Originally Posted By: randomhero439
There motor oil isnt terrible, spend the extra $1 and get Prestone or Valvoline.


^^ This

JP
 
Genuine GM fluid, as it has a special long life additive unique to GM.

Note that there is no published recommendation on most GM cars or trucks for brake fluid flush. That's a clue.
 
Originally Posted By: michaelluscher
I hear Motorcraft's DOT 3 fluid has the highest boiling point of any non racing .3 fluid,
500° IIRC.


You are correct. I sell a lot of it to road racers who use it just for that reason.
 
Well...the DOT brake fluid specs are minimums. Some brands exceed the minimums. The Ford brake fluid has a higher dry boiling point, so it is great for racers who change their brake fluid often. It has a mediocre wet boiling point. It is no benefit for those of us who change the fluid every two years or longer or never. DOT4 fluid is a slightly different chemical composition (that's how they get the higher wet boiling point) and might be incompatible with the elastomers in some brake systems. I suspect that DOT4 caused the seals on my Toyota master cylinder to fail before its time.
 
Wearever is BOGO at Advance right now. Just get that, fluid is fluid as far as the average car is concerned. I got 4 quarts last month on that BOGO deal and thoroughly flushed my Explorer's system.
 
Originally Posted By: another Todd
Originally Posted By: Loobed

The best DOT 3 fluid is DOT 4 fluid.

+1. Why buy dot 3 when dot 4 is only slightly more and has a higher wet boiling point?


I have seen different opinions about DOT 4. Are these statements in this Stop Tech white paper true?
http://www.stoptech.com/technical-support/technical-white-papers/brake-fluid

"A seldom talked about characteristic is that because of this chemistry, the DOT 4 fluid will have a more stable and higher boiling point during the early portion of its life, but ironically once the fluid does actually begin to absorb water its boiling point will typically fall off more rapidly than a typical DOT 3."

"This does not mean that DOT 4 fluids are necessarily better than DOT 3 fluids. Remember, the boiling points listed are minimums. There are certain DOT 3 fluids with higher boiling points than some DOT 4 fluids."

"The real differentiating factor is that DOT 4 fluid should be changed more often than a DOT 3 fluid, because of the effects and rates of water absorption."

Comments?
 
Originally Posted By: doitmyself
Comments?


At least it passes the smell test, as it were, and I've read much the same information elsewhere. A lot of European cars do recommend brake fluid flushes and they do often, coincidentally or not, call for DOT 4.

So, do they call for the flushes because they're meticulous about maintenance, or because they might be high performance applications, or because it's DOT 4?
 
The reason why you may want to stick with DOT 3 over DOT 4 is for the same reason OEMs use it, and it's not because of slightly lower cost. It's because the difference in minimum boiling point dry and wet between DOT 3 and DOT 4 isn't that much to begin with, and DOT 4's wet boiling point drops much faster than DOT 3's. DOT 3 absorbs more moisture than DOT 4 which is better than it settling out and corroding parts of the brake system internally.

If your racing or driving hard and getting the brakes really hot and are going to change the brake fluid evry race, season, or 1-2 years then you might realize a higher boiling point with DOT 4. But otherwise if you don't want to change brake fuid every 1-2 years DOT 3 makes more sense.

Also although DOT 3 and DOT 4 are said to be compatible, if the factory fill is DOT 3, it could be one of the higher corrosion inhibited "lifetime fluids" as ACDelco claims. If you decide to change out brake fluid, it could make sense to use OE DOT 3 if it has a longer service life.
 
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Originally Posted By: another Todd
Nothing in the linked article makes me want to go back to Dot 3 from Dot 4. I only use Dot 4 labled as Low Moisture Activity (LMA).


Valvoline's DOT3/DOT4 fluid is labeled as LMA.
 
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