Thread: 3/16" vs 1/4" brake line

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Actually, the smaller diameter tubing will increase brake pressure for the same pedal movement. Will it be a problem? Maybe not...

The proportioning block may equalize any difference (?)

Two cents,

-Chris

I would say that another way. The smaller diameter tube decreases overall system volume slightly, but once filled you are simply moving fluid from the master cylinder to the slave, and both volumes and areas are unchanged. Your system pressure remains the same - you will see no difference between 3/16" and 1/4" lines. Jack has it right, IMO. Just my $0.02.

Originally Posted by skids72

Actually, the smaller diameter tubing will increase brake pressure for the same pedal movement. Will it be a problem? Maybe not...

The proportioning block may equalize any difference (?)

Two cents,

-Chris

Chris,

Again, I disagree. Your statement is contrary to basic hydraulics. There's no reason for the smaller diameter tubing to increase brake pressure for the same pedal movement. The tubing is just a conduit between the two pistons. You get the same pressure whether you use 3/16" tube or 2" tube.

A-Rod,

Frankly, that statement on Inline Tube's website is pure baloney. He's right about the amount of pressure required for disk and drum brakes, but he's totally off base about the effect of tubing size on pressure. He doesn't even need to take fluid mechanics. Eighth-grade physics would suffice.