brake line diameter

Is there a difference in the diameter of the brake line going from original drum to disc brakes?I am plumbing my brakes for my new disc brake setup and just though of this.I have the Heidts standard 11 inch GM brakes.I went with a 3/16 brakeline to use.Will this work or do I need to get a larger diameter line because of going from drum/drum to disc/drum.


Thanks....Joe

3/16 is ok

I was told that the brake diameter didnt matter for the pushing power, but that it would let the brakes release faster.

I was told that the brake diameter didn't matter for the pushing power, but that it would let the brakes release faster.

There are two schools of thought on the 1/4 vs the 3/16 lines. I like the 3/16 while others like the 1/4 line. I like the 3/16 when it comes to disk brakes cause we all know that disk require higher line pressure to operate.

My thought is this. the 1/4 line carries more volume than the 3/16 line there by making the pedal harder to push. Other state that pressure is the same regardless of line size to that point I agree.

My contention is this. take a 5 gallon bucket full of water and a 10 gallon bucket full of water. If one applies 1lbs of pressure to each the both will register 1lbs of pressure. Now pick up and move the 5 gal. bucket 1 foot, then pick up the 10 gal. bucket and move it one foot. Which uses less force? It takes twice a much force to move the 10 gal. as did the 5 gal. bucket. now apply the force that it took to move the 10 gal. bucket on the 5 gal. bucket. moves easier?

With line size you are moving volume. The the greater volume the higher the effort. If you apply the same force to a 3/16 line as you did the 1/4 you archive higher line pressure simply because you are not moving as much volume.

I expect to here from Pascal on this.:) :D

Given your example, Pascal would ask the question - How much more pressure can you generate in a 3/16" line than a 1/4" line using the same master and slave cylinders?

Given your example, Pascal would ask the question - How much more pressure can you generate in a 3/16" line than a 1/4" line using the same master and slave cylinders?

I am stating Force or effort not pressure. Pressure is a direct effect of the affect of force.

M/C and slave cylinders given the same. The amount of line would be the variable. 12" of 1/4" line VS 12" of 3/16" line, force would be negligible. 25' of 1/4" line VS 25' of 3/16 line, the force difference is measurable.

The reason I use 25ft is because that about the amount of line on the average intermediate car.

Mike, I agree with you on pressure. Where we diverge is in effort or force needed to generate pressure.

The next question Pascal would ask is - how much more force? What's the math behind this?

Please look at this thread- this subject has already been HEAVILY debated!

http://www.stevesnovasite.com/forums/showthread.php?t=50757&highlight=brake+line+misconceptions

Please look at this thread- this subject has already been HEAVILY debated!

http://www.stevesnovasite.com/forums/showthread.php?t=50757&highlight=brake+line+misconceptions


agreed I'm outa here