OEM brake fluid?

H3br3w_Ham3r

Member
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2008 Mazdaspeed3
Anyone know what it is so I don't have to flush the whole system and can just top it off? Also does clutch use the same reservoir? This would mean I need to flush that line as well if I replace the OEM fluid with the good high temp stuff right?

Haven't done anything with the brakes yet and the pedal has gotten a bit soft now after 5 auto crosses and 4 track days. The stock brakes are impressive but I am going to upgrade them next year.
 
its just DOT3 s***... flush it out with QUALITY DOT4 or DOT5.1 and you and your car will be happy
 
I'm not familiar with what the difference between these fluids are. Care to enlighten me?

I thought that this article summarized it better than I could have. http://au.geocities.com/ozbrick850/brake-fluidtypes.html

I think a main reason ppl say not to use DOT5 on our cars is because we have DOT3 from factory. When flushing your brakes it is hard to know if all of the old fluid has been removed.

"DOT5 does NOT mix with DOT3 or DOT4. Most reported problems with DOT5 are probably due to some degree of mixing with other fluid types. The best way to convert to DOT5 is to totally rebuild the hydraulic system."
 
I was told that ATE Super Blue is a good brake fluid for track days.

But was also told that the down side to it is that it has to be changed more often because it absorbs moisture quicker.
 
I have ATE superblue DOT4 brake fluid. The only downside I have heard of is that it stains the inside of the brake lines blue. No1 ever looks at the inside of the brake lines, so it doesn't bother me. I though DOT4 absorbs less water than DOT3? Correct me if im wrong. I think the differences between DOT3 and DOT4 are dry boiling points, wet boiling points, and water absorption. But I am no brake expert.
 
DOT 5 is silicone-based, and not compatible with PEG-based DOT 3, DOT 4, or DOT 5.1

DOT 5.1 has a PEG-base like DOT 3 and DOT 4, and can be mixed with them.

And yes, the higher boiling point fluids are less hygroscopic (meaning they will absorb less water) and therefore need to be flushed more frequently. :)
 
I've decided to go with more DOT3 fluid for the time being. Anyone have a brand name that they could recommend? Looking to flush my system some time this week.
 
And yes, the higher boiling point fluids are less hygroscopic (meaning they will absorb less water) and therefore need to be flushed more frequently. :)

Huh??
Run that by me one more time...
Brake fluid needs to be flushed because it absorbs moisture if it is LESS hygroscopic and absorbs LESS moisture, then surely it would need to be flushed LESS frequently........ no.

So something you typed doesnt add up.
Usually I agree with everything you type Nliiitend1 so please clarify for me??
 
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Huh??
Run that by me one more time...
Brake fluid needs to be flushed because it absorbs moisture if it is LESS hygroscopic and absorbs LESS moisture, then surely it would need to be flushed LESS frequently........ no.

So something you typed doesnt add up.
Usually I agree with everything you type Nliiitend1 so please clarify for me??

I'm sorry. I sort of misspoke (typed?). :o

I meant to say that the silicon-based DOT 5 fluid (a higher boiling point fluid, although I think technically the PEG-based DOT 5.1 fluids have higher boiling points than DOT5...) is less hygroscopic than the PEG-based fluids and therefore requires frequent flushing because water pools and collects in the system (which if left unchecked can lead to catastrophic rusting of the system's hard-lines and calipers).

The water is there whether the fluid absorbs it or not. The water-absorbing property of the PEG-based fluids actually makes it safer (for the health of the braking system) to run extended fluid-change intervals...

Sorry for the confusion.
 
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I'm sorry. I sort of misspoke (typed?). :o

I meant to say that the silicon-based DOT 5 fluid (a higher boiling point fluid, although I think technically the PEG-based DOT 5.1 fluids have higher boiling points than DOT5...) is less hygroscopic than the PEG-based fluids and therefore requires frequent flushing because water pools and collects in the system (which if left unchecked can lead to catastrophic rusting of the system's hard-lines and calipers).

The water is there whether the fluid absorbs it or not. The water-absorbing property of the PEG-based fluids actually makes it safer (for the health of the braking system) to run extended fluid-change intervals...

Sorry for the confusion.

OK Now I understand, I didn't realize you were referring to the DOT5.
Understand now and agree...... go figure.
 
I don't imagine that would be a brand I could get at an Auto zone or Advanced auto parts would it? I need the fluid soon and can't wait for shipping. I was looking around at brands and was thinking of Prestone High temp DOT3.

You might be able to find the Ford HD stuff marketed as Motorcraft Heavy Duty...

I've used the Valvoline Synthetic DOT 4 (possibly marketed as "SynPower") before in a pinch (it's available almost everywhere).

I wouldn't think twice about mixing it with the OEM DOT 3 fill...It'll be just fine. :)

OK Now I understand, I didn't realize you were referring to the DOT5.
Understand now and agree...... go figure.

Yeah, sorry for not being more specific...it was one of those instances where I was completing my train of thought in my post before laying the complete foundation for it...:)
 
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You might be able to find the Ford HD stuff marketed as Motorcraft Heavy Duty...

I've used the Valvoline Synthetic DOT 4 (possibly marketed as "SynPower") before in a pinch (it's available almost everywhere).

I wouldn't think twice about mixing it with the OEM DOT 3 fill...It'll be just fine. :)



Yeah, sorry for not being more specific...it was one of those instances where I was completing my train of thought in my post before laying the complete foundation for it...:)

Ya I got the valvoline stuff. It said DOT 3 and DOT 4 on the bottle which made no sense but it passed the DOT4 tests so I'm assuming it's just a DOT4 that they say will work in DOT3 systems. I'm going to flush my system out completely tomorrow.
 
all of these recommendations are based off of old info... valvoline's formulation has changed and they no longer have the gold bottles of DOT4.... the new white bottle DOT4s aren't as good... ford's HD fluid is no longer made either... whatever they have now isn't as good as the old days

the new valvoline isn't too shabby still but the boiling points have decreased...
as far as off the shelf, easy to buy stuff... there's only 2 brands I'd recommend.. prestone DOT4 which is cheap as hell and while the boiling point isn't that great compared to the exotic stuff, it works and you can find it at walmart
castrol GTLMA DOT4... found at pepboys for like 5-6 bucks a pint... VERY good stuff and it has low moisture absorbtion properties... don't know what they did but it works... on my sparingly driven van, the brake feel still is great since I flushed it a year ago with this stuff... the brake pedal never felt this good until I used this fluid, not even with the ford HD stuff

for the expensive s***, hit up the motorcycle shop and I recommend motul RBF 600 which is a DOT4... motul DOT 5.1 works great too and is suitable for cold climate areas where the vehicle has ABS... it has a lower pour point and thus allows for ABS and clutch cylinders to still work right in sub zero temperatures

ATE superblue is the other brand lots of other people swear by.... I don't use it because its blue and it makes it harder to eyeball the condition of the fluid.... tech inspectors at race tracks will think your brake fluid is BAD too because it's so dark!
 
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