Upgraded Brake Calipers and Brake Line Sizes

[Fouledplugs]

Where is the threshold for the requirement for 1/4 inch hard brake lines?

I understand that 3/16’s is the go to for most, if not all hard lines. When adding bigger brake calipers and larger rotors, is there any reason there that requires the bigger 1/4 inch hard lines?

 

[mrblaine]

Where is the threshold for the requirement for 1/4 inch hard brake lines?

I understand that 3/16’s is the go to for most, if not all hard lines. When adding bigger brake calipers and larger rotors, is there any reason there that requires the bigger 1/4 inch hard lines?

Rotor size has zero to do with it. I'd also like to get someone to explain the use of 1/4" hard line any where since the fluid volume to move a caliper piston is so small that I don't see how it can make any difference.

 

[Fouledplugs]

Rotor size has zero to do with it. I'd also like to get someone to explain the use of 1/4" hard line any where since the fluid volume to move a caliper piston is so small that I don't see how it can make any difference.

Got it, I’ll stick to the 3/16 stuff.

The only justification i can think of would be swapping to a huge 6 piston caliper that moves a lot of fluid.

Are the long runs from front to back down the frame still 3/16 on factory TJ’s?

 

[LukesfirstJeep]

The only justification i can think of would be swapping to a huge 6 piston caliper that moves a lot of fluid.

My only experience with swapping calipers and master cylinders is with motorcycle brake systems. I've never changed the line size when going to bigger calipers. More than once, I've installed a master cylinder with a smaller bore to lessen the amount of brake lever force needed for the same braking force.

 

[mrblaine]

Got it, I’ll stick to the 3/16 stuff.

The only justification i can think of would be swapping to a huge 6 piston caliper that moves a lot of fluid.

Are the long runs from front to back down the frame still 3/16 on factory TJ’s?

Yes, 3/16" from nose to tail. Even a big 6 piston fixed doesn't require much volume to move all the pistons to full lock. The total movement for each piston is sub .030. You can do the math but it isn't much.

 

[Fouledplugs]

Yes, 3/16" from nose to tail. Even a big 6 piston fixed doesn't require much volume to move all the pistons to full lock. The total movement for each piston is sub .030. You can do the math but it isn't much.

Thanks.

 

[LukesfirstJeep]

Yes, 3/16" from nose to tail. Even a big 6 piston fixed doesn't require much volume to move all the pistons to full lock. The total movement for each piston is sub .030. You can do the math but it isn't much.

I agree. I've done the math, but it was in the last century. Normally, master cylinder bore size has a much bigger influence than line size on brake performance.

 

[Fouledplugs]

I agree. I've done the math, but it was in the last century. Normally, master cylinder bore size has a much bigger influence than line size on brake performance.

Understood, was orginally curious on what typically is installed or modified that requires a 1/4 hard line.