New Brake Fluid

[sunfire]

Does anyone know what a typical car's brake fluid capacity is? I'm thinking about using the turkey baster method to replace the brake fluid. I want to know how may times I have to do this to get most of the factory fill out.

I'm leaning towards the Valvoline Synthetic since it has the highest highest dry boiling point. But I also have Preston, Supertech, Wearever brands available to me.

BTW, I have a 2005 Corolla which specs DOT3.

 

[Quest]

different car designs call for different reservoir size for master cylinder.

Typical corolla shouldn't take more than 200~250ml to fill (from dry) so you have to work things out yourself: in the case of flush and fill, try 750ml.

Q.

 

[tom slick]

The brake fluid doesn't circulate, once you R&R the fluid in the reservoir you are not going to get any more "factory fill" out. The lines, calipers and ABS valves will still have "factory fill".

 

[GMBoy]

The Valvoline Synpower DOT 4 you're talking about is great stuff. BUt do yourself a favor and do a full brake bleed to get all the benefits. The worst fluid is right at your calipers, not your master cyl.

 

[sunfire]

Thanks for your input. I will bleed the brakes as it is way over due.

 

[tom slick]

for bleeding I'd buy a quart to flush through the system.

 

[GMBoy]

Originally Posted By: tom slick
for bleeding I'd buy a quart to flush through the system.


X2. Whenever I've bled brakes I never used more than 1 quart.

 

[artificialist]

I have always needed a full quart for flushing a car with ABS brakes. Most non-ABS cars I have worked on only need around .5-.8 quarts.

DOT4 is a good replacement for DOT3. I have put Valvoline Synpower DOT4 in DOT3 systems several times, and every time I was amazed at how much cleaner the fluid would stay.

 

[Kestas]

For reference, Mercedes specifies bleeding 250ml from each corner to exchange the brake fluid. So one liter should do it.

 

[mechtech2]

A turkey baster flush on a power steering system works quickly.
It does not on a brake system. It mixes, but much more slowly.
But it IS great maintenance, and a very good thing to do.
A real flush is of course proper every 2 years or so.

 

[c3po]

mechtech2, if we sucked the brake fluid out once a month for the life of the vehicle would this be just as good as flushing out the brake fluid every 2 years.

The reason I ask this is because when I had my brakes flushed, the brake fluid that came out was fairly clear except for a little bit of dark brake fluid.

 

[Saab9-3]

Maybe I misread, but Valvoline does not have the highest dry boiling point of the brake fluids available. Regardless, I am sure 480F dry boiling point will do just fine for a little corolla.

 

[Ken2]

Dry boiling point isn't very meaningful except for a very short time after you change the fluid. Wet boiling point is more meaningful, because the fluid starts to immediately absorb moisture from the air.

I've flushed the brake system with ATE's blue dyed fluid, and it takes less to change the system than we need when there is a color change to show the flush. I agree, use a quart, and flushing a bit extra isn't a bad idea.

 

[mechtech2]

c3po - Every month is way to often.
But a couple of times a year is cheap, quick, and easy. And quite beneficial.
This would allow at least a much longer interval[for bleeding] than if the fluid was never kept clean.
That said, it is a good idea to at least gravity bleed the system every couple of years.
I think brakes parts would last 2-3 times longer when performing both of these things.
A direct answer to your question is yes, it probably would work, but no one could make promises. It could never hurt, except for $20 extra of brake fluid every year.

 

[c3po]

mechtech2, sorry about the every month thing, I usually sucked the brake fluid out every 3 months which was about the time I did an oil change.

 

[Barkleymut]

I just want to be clear on this as I do NOT work on my brakes very often. If you have a resivor why would there not be ANY circulation of fluid? I would think the turkey baster method every few months would be great.

 

[Big Jim]

The brake fluid does not circulate. At most there may be a very slight bit of migration from applying and releasing pressure, but the amount of mixing is insignificant.

The reservoir is to provide added fluid as the brake pads/lining wears. As the pads wear, the pistons reside closer to the rotor, creating more space in the caliper that needs to be filled with fluid. To a lesser extent, the same thing happens with drum brakes.

If you think it helps to do a turkey baster suck and fill to the master cylinder then do it, but there is no basis in fact for this being anything more than very slightly beneficial. You will not get rid of the crud that builds up closest to the wheels without a flush/bleed. Sucking out the master cylinder and refilling it without the rest of the work is a practice that would most fit a used car lot that is trying to make the car look better than it is by having a clean looking brake fluid bottle when someone opens the hood.

 

[Kestas]

A couple years ago I posted a challenge to anybody who was curious if new fluid in the master cylinder would mix all the way to the calipers.

After flushing all the brake fluid, exchange the fluid in the master cylinder with blue fluid. Then six months down the road flush again, and note the color of the fluid immediately coming out of the caliper. This would put an end to speculation and misinformation.

As yet, nobody has reported back. It would be interesting to see what the effect Brownian motion has on brake fluid.

 

[trynew]

This topic has been debated a few times in the past on this forum. Almost all of the arguments either way (including this present discussion) seem to be based upon "logic" with little factual evidence to back up the opinions, yet the writers are absolutely sure they are right.

Here are two quotes from the past, one for and one against:

Quote:
Yes. There is a lot of movement.
Some more than others, and an ABS system isn't certain.
At the shop we have performed and recommended turkey baster type flushes for people with economic restrictions. It usually helps or fixes some problems, and is certainly good maintainance.
My latest experience was a Chevy work truck. We had the owner suck out his master cyl and clean it, then refill with fresh fluid every couple of days. It would get black rapidly, then started to clear up, and his rear brakes started working properly again.
Of course bleeding the system is faster and better. But we have to deal with people with no money and broken off rusted bleeders.
I turkey baster my personal vehicles as a regular maintainance procedure
-quick and clean for PS and brakes.


Quote:
No it wouldn't. In fact I tested this by emptying out 3/4 of the resevoir of brake fluid and after about 500 miles of driving I could clearly see the line of new and old fluid in the resevoir.


I tend to lean toward believing the first quote is more representative of most vehicles. I also suctioned out a brake resevoir several times on an old vehicle and the fluid gradually went from dark to light.

 

[moribundman]

Originally Posted By: trynew
I tend to lean toward believing the first quote is more representative of most vehicles. I also suctioned out a brake resevoir several times on an old vehicle and the fluid gradually went from dark to light.


Based on my experience, the brake fluid does not turn noticeably darker in the reservoir during the specified service interval. When I crack a caliper bleeder, the very first amount of fluid (maybe 3 ml) comes out with a puff of darkness. From then on the fluid has the same hue.

Maybe I will suck out the fluid from the reservoir and add ATE Blue. Then after a year, I will bleed the brakes. Then I'll know if the blue fluid has mixed thoroughly with the other fluid throughout the whole system.