Do brake lines need to be of equal length?

Clois Harlan · #1 (**permalink**) 03-01-2006, 09:21 AM

This occured to me last night while I was working on my calipers. How important is it to have your front brake hard lines of equal lenth from the TEE? Reason I am asking is that I am going to re-plumb my pick up points for my flexiable lines from my caliper to my hard line.

Clois

jarendall · #2 (**permalink**) 03-01-2006, 09:35 AM

ABS brakes have a balancer, conventional brakes do not, so the more equal the lines are in lenth the better your braking will be, in theory, however it is argued that once you properly bleed the system the pressure should be the same through out and line lenth shouldn't matter, so I decided to make my lines equal just to be safe.

951mat · #3 (**permalink**) 03-01-2006, 09:37 AM

If I understand correctly, can't imagine its important. You saw mine the other day on my lonestar. The "T" on my car is on the inside of the left frame rail. Only goes +/- 1 foot to the left wheel and several feet to the right. All the caliper should care about is pressure. Shouldn't matter how long the hardlines are.

mat

CSCHWER · #4 (**permalink**) 03-01-2006, 09:37 AM

Clois,
I was going to say "not very important." but an engineer might give you a different answer. How did the pedals work out?
Chet

Richard Hudgins · #5 (**permalink**) 03-01-2006, 10:09 AM

Clois,

Brake line length has no effect on system pressures.

You are dealing with a non compressible fluid.

There is little flow involved, so any pressure drop calculations that are used for tube flow are not applicable.

Think of it this way: If you have a piece of steel tubing two feet long and you push it against the floor with 20 lbs of force, you get 20 lbs of force at the floor.

If you have a three foot piece of steel tubing and you push it against the floor with 20 lbs of force you still get twenty pounds of force at the floor.

(Plus the extra weight of the longer tubing of course.)

auto10x · #6 (**permalink**) 03-01-2006, 10:44 AM

Pascal's Law says different length brake lines won't matter.
auto10x
Bill

wtm442 · #7 (**permalink**) 03-01-2006, 10:51 AM

Just make the lines as close to equal as possible without jumping thru hoops, and do NOT sweat the small stuff. I have ABS on my daily driver and the lines are no where close (> 2 feet) to being equal.

Power Surge · #8 (**permalink**) 03-01-2006, 11:26 AM

The only way unequal lines would matter, is if you had unequal lengths of something that expanded, like a standard rubber line. Then you could have different braking pressures to the calipers from different amounts of hose expansion. If you are using steel hard lines and braided flex lines, it shouldn't matter at all.

Rick Parker · #9 (**permalink**) 03-01-2006, 12:04 PM

Absolutely not!

trularin · #10 (**permalink**) 03-01-2006, 01:09 PM

I made mine equal length, but it doesn't matter. I did it so I can buy standard length lines anywhere.

Clois Harlan · #11 (**permalink**) 03-01-2006, 01:13 PM

I didn't think so but I thought I would throw it out to the experts. Glad to here I was thinking clearly.

Chet the pedals are working very well. I just needed to remind myself that they are much easier to adjust clearances before you install them rather than after, thank you again.

Mat,

Would you like to drop by Sunday afternoon? I will not be home until late Saturday night.

Clois