Brake fluid ?

[tvl]

Originally Posted By: artificialist
Every time I have used DOT4, the system stayed cleaner, despite the fact that I'm told DOT4 absorbs more moisture.

Valvoline and Pennzoil make great DOT4 approved brake fluids.

Don't get duped into the hype of "Full synthetic brake fluid." DOT 3 and 4 brake fluid is a glycol ether, which must must be made synthetically.


So, I have read a lot here and other places about mixing brake fluid and most say NOT to mix.

My question is simple: I just purchased a bottle of Valvoline Synthetic DOT 3&4 brake fluid. It clearly states: "Mixes well with conventional fluids". Is it acceptable to mix the contents of this bottle with conventional DOT 3 brake fluid?

If not why?

 

[moribundman]

Originally Posted By: artificialist
Every time I have used DOT4, the system stayed cleaner, despite the fact that I'm told DOT4 absorbs more moisture.


DOT 4 fluid absorbs moisture faster than does DOT 3 fluid over the same period. Whether or not it absorbs "more" moisture I do not know. Is there a saturation point?

 

[DrD]

Dot 4 will mix with DOT 3 just fine. Generally speaking, the higher performing brake fluids are more hygroscopic - however, you'll often find that the wet boiling point of a DOT 4 (and certainly a DOT5.1) will be as high or higher than the dry boiling point of a DOT 3. (still, faster water uptake = higher potential for corrosion - fortunately, there is negligable humidity here - two or three years on the fluid and it's just a bit darker than fresh out of the bottle)

 

[james49]

There are some Dot 5.1 brake fluids that also meet Dot 3 & 4 specs.

 

[kgb007stb]

Originally Posted By: The Critic
I used a Motive Power Bleeder with the GM adapter on my Saturn. It took less than eight minutes to flush one quart of fluid through all four lines.


Now I feel so bad as it took me 24 minutes to flush two Saturns.

 

[The Critic]

Originally Posted By: kgb007stb
Originally Posted By: The Critic
I used a Motive Power Bleeder with the GM adapter on my Saturn. It took less than eight minutes to flush one quart of fluid through all four lines.


Now I feel so bad as it took me 24 minutes to flush two Saturns.

Pumping the brake pedal prior to starting the flush and using 20 psi works wonders!

 

[wiswind]

Regardless of the fluid....I prefer to bleed at each wheel at LEAST every 2 years.....there can be a lot of junk build up at each wheel in that time....while the fluid in the master cylinder looks great.
So you won't know about the dirty fluid until you bleed it.

I have used slotted rotors, Brembo brand, but not drilled.
I would go with a reputable brand name.
It is IMPORTANT to follow the instructions that come with the rotors as to installation......they are not interchangable from right to left side.
The ones that I got had a diagram....and the installation was backward from some other vehicle installation as far as the slot direction.
You want the vents inside the rotor to be correct so that they will cool properly.
On my vehicle.....the visual aspect was not critical at all.....as the rotor do not show.

 

[Ken2]

Quote:
My question is simple: I just purchased a bottle of Valvoline Synthetic DOT 3&4 brake fluid. It clearly states: "Mixes well with conventional fluids". Is it acceptable to mix the contents of this bottle with conventional DOT 3 brake fluid?
Ah, the triumph of marketing. ALL brake fluid is synthetic. There is nothing natural about a polyglycol ether fluid.

Yes, any DOT 3, 4, 4+, or 5.1 fluid will mix with another. As always, they must not be mixed with the silicone DOT5 fluids, and those silicone fluids must never be used except in a system designed for them.

 

[labman]

There are others like me that believe picking a product and sticking with it. Thus I haven't used anything but Prestone DOT 4 or perhaps longer ago, what they labeled Disk Brake Fluid. I have mixed it with OEM fluid.

I have used little except Pennzoil Dino since Ashland Chemical threw me out in 1976. I am still Valvoline Gear Oil. I have used Lubrimatic grease since the 70's too.