The Stovebolt Site Forums The Shop Area Driveline What's the Brake Line Volume?

Just sittin’ here over my coffee and got to wondering how you would figure the volume of a brake line. I pulled all of the lines and cylinders and have to refill the system, so I was trying to estimate how much fluid they will hold if I have the total length. Of course to start with I can figure the volume of a cylinder using the inside ID of the tubing but then comes the conversion to liquid volume.
So maybe one of you math wizards can help me out with a formula and not in metric please, I’m an American!
Denny Graham
Sandwich, IL

Less than a quart. Or maybe more. Depends on how much hits the floor when you bleed the brake lines.

Here is a link to find volume of various shapes, hope this helps.
http://grapevine.abe.msstate.edu/~fto/tools/vol/index.html

I just put all new brakes on my '54 GMC, took way less than a quart even with bleeding.

1.I would do the math to get the square inch volumn of the lines.

2.Measure the volumn in square inches of the container the fluid is in and do the math to determine the square inches it takes to hold the amount of fluid thats in the container. (measure only the occupied area of the container)

For intance you may have a container that is 12 square inches with 12 ounces of fluid in it. Which equates to 1 ounce per square inch.

3.With the results of those two calculations you can quickly determine the amonunt of liquid it will take to fill the lines.

I am sure someone else has a better way but I think this will get the result.

cripes, I just go to the store and get a smallish bottle of brake fluid - doesn't matter what ya get it'll always be a bit too much or not quite enuff - get 2 so you can top it up when necessary

Bill

Hey Bill, I agree with you and that is exactly what I do.I buy those small tins and keep some on hand.

Denny has a reason,unknown to me,for asking about a formula and I suggested how he might do the calculations.

Happy New Year,Hobert

I just bought a gallon of brake fluid,cuz I plan to flush and bleed the heck outta my '62s brakes,see if I can bring all of it's wierd behavior to a stop. No pun intended.
Speed

Cripes Bill, can't a guy just wonder bout those kind of things over a cup o' Joe??? No big thing, that thar volume, just a passing thought. I got all kinds of those trivial little guys running cross the old brain, specialy when I get up at 04:00 in the mornin’. I’d really drive ya nuts if I told ya what was goin through my head this morning.
I’ve got a couple of gallons or dot3 on the shelf and more in the pressure bleeder. I'm just one of those guys that picks everything to pieces, ya know! I yust vant to clutter up my mind with tons of details, and was just curious as to exactly how much the system would hold.
After all, don't ya want to know just how much your fuel tank holds? Or maybe how much your cooling system holds? The spec-sheet gives ya all that, why not, brake fluid capacity? I used to know how much my bladder holds but since I've gotten so old, I'm not sure bout that any more, I’m probably gonna need to find out what the volume of a Depends is in the not to distant future.
Apache, I like your idea for calculating the volume of a beaker graduated in liquid. Thought there might be an online calculator that would have a conversion but taint been able to find one.
Denny Graham
Sandwich, IL

1 cubic inch = .554 ounce US

http://www.onlineconversion.com/volume.htm

Denny Graham
Sandwich, IL

Brake fluid has limited shelf life.
It attracts moisture, which is one reason for regular replacing with fresh fluid to protect the lines from corrosion inside.

you gotta be pulling our collective leg, right, Denny? illegal immigration, world hunger, the war in Iraq, just how crooked is our president? , the downward spiral of the U.S. dollar, global warming or the lack therof,
Think about these until it is really time to get up.

and the best reason to keep it in an airtight container ... and never buy it in bulk

Denny, figured you were just spinnin the wheels when you mentioned coffee

Bill

Man 65, that's heavy, if your thinkin’ about all that over your cup o' java in the mornin' I feel for ya. Just look at the time ya all wasted reading this thread, when you could be saving the world!
I usually have about two or three hundred of those crazy little things running around the old brain all the time, every once in a while I grab one and dissect it. That's one of my problems, way to much on the plate for an old guy to handle sometimes. I can't look at anything, with out wondering, I was going to make a point of taking a factory tour every week when I retired to find out But alas, here I am, almost into my third year of retirement and tain’t even tookin one trip yet!!!
You must be a young dude, some day you will realize that all those things you mentioned have been with us since time began, besides, thinking about things I can't do anything about is to me, a waste of energy. Now learning as much as I can about this old truck and paying attention to all those little details is something that's within my grasp.
Now, all I have to do this week is figure out how they got those round staples in the beaded window cats whiskers on the window garnish, I wonder, "How'd they do that???"
Denny Graham
Sandwich, IL

Yeh, Denny, I'm just a pup. That "65" on my userid represents the year I graduated from high school.....been a while.

I've been retired for nearly 8 years and I've never had the time to dwell on anything like 'brake line volume' for much time at all.

I'm not thinking about any of those things, I've got things to do.

SCS, just pullin' your jeeber ya know! Class of "60" here, you are, just a pup, ha! All those old retired dudes were always tellin me, "Since I retired, it seems like I have less time then when I was workin'" I thought they were yust kiddin' but now that I'm one o' them, it sure seems like that's true, I can't figure out why. Maybe it's because I'm thinkin bout those dumb little things like Brake Fluid Volume.

Denny Graham
Sandwich, IL

p.s.
Chevrolet Truck Data Book for Chevrolet Salesmen, ©1949, pg 199,
Hydraulic Brake System: Capacity……..3/4 tp 1 pint (approx), Delco super 10.

Whew, now I can finally quit spinnin’ my wheels and move on!!!!!

Just take the area of a circle times the length for the brake line.... ie pie R square for the area where pie is 3.14, R is 1/2 diameter of tube which is then squared (multiplied by itself)

A 10 foot length of brake line that is 1/4" inside diameter would go like this....
Volume=(10'x12")x(3.14x(0.125"x0.125")) [do the multiplication inside the ()s first.
Volume=120"x(3.14x0.016)
Volume=120"x0.049
Volume=5.888 cubic inches; then 1 ci =0.554 fl oz
so Volume=5.888x0.558
Volume=3.263 fluid ounce

So just plug in your length and tube diameter for the imaginary numbers I used above and you'll have it. As my high school physics teacher used to say, "I leave that as an exercise for the student!". I hated to hear that. Or as Jeff Foxworthy says; "When did they start putting letters in the formulas", when asked to help with math by one of his daughtors.

Oh by the way, I had to go to my trusty HP calculator to look up the cubic inch to fluid ounce conversion. I like what Einstein had to say about that; "Why clutter up your mind with facts you can look up when you need them".

Class of '65 too.

1/4" brake line is acually .1875" (3/16")inside Wade. Like I posted earlier, Data Book has the specs.
Thanks all, on to more important things.
Denny G