The Stovebolt Site Forums The Shop Area The HiPo Shop Brake line size

Just trying to find out what everyone is using as a standard size brake line. I was at the store last night to pick up some and they have 1/4" and a smaller size. I held off to go check what is on the rear that I installed and it was smaller line the the original stock that came on my 52 Chevy. I am adding an under the floor booster/ Master setup and when I checked the extra one that I have I realized that they used the 1/4" on some lines and the smaller on the other. I think the other size is an 1/8" or they are 5/16" and 3/16" I cannot remember off the top of my head. Is there a one size for all or at least a guideline for what to use? Thanks

Forgot to mention that I have a disc brake setup now in the front also.

3/16 and 1/4 are the two common sizes used on brake systems, it varys from system to system. Some use all one size, but many use a mix. Since you're running an aftermarket brake system, OE sizes won't really matter. Sounds like they have it setup for 1/4 to the front, 3/16 to the rear.

I have a aftermarket set up on my 49..Disc front ,drum rear...I used 3/16 up front...1/4 to the rear which goes into a rubber hose and tee,then 3/16 to each rear wheel........dave

Disc needs more fluid volume transferred to move the piston, hence the larger line.

Fluid volume doesn't necessarily relate to pressure. Most aftermarket (front) disc conversion kits use 3/16 front and 1/4 to the rear. You will find that the proportioning valves are designed for 3/16. I have installed numerous kits on a variety of vehicles and have not had a problem with this configuration.
Fred

rfs56trk,
that is correct it's more about pressure transfer, there's very little fluid movement. most modern disc brakes use 3/16 hard lines. i think the only reason ( & this is just an opinion ) that some ran 3/16 to the front & 1/4 to the rear was to avoid confusion.
robert

I was planning on going 3/16 all the way around based on the comments and I know the rear that I have in there used 3/16. Thanks for all the great input that's what I was looking for. Now I can move forward on the project.

there's very little fluid movement

Except for that... pedal thingy, and those little whatcha-ma-callit caliper pistons.
Where does that motion go?
Fluid always moves.
Disc brake calipers require more volume transfer than drum brake cylinders.

I've seen them both ways on the OEM brake systems.

3/16 going to the front is a smaller line then 1/4 or 4/16 going to the back. If Discs take more fluid to opperate, then that meams more fluid would move farther in a smaller line then a bigger one. Fluid only moves if it has some place to go. If one side of a wheel cyl is froozen up, the brakes will only wear on one shoe and will not on the one side that is froozen up. That happened to me. I needed to replace the wheel cyl all the bolts broke off. The 2 mounting ones, the bleeder and the line bolt stripped.

I will be replacing with a dual 7 in power brake booster and replacing all my lines. I have a 53 long box truck with a newer 14 bolt 3.75 ratio rear end. I do not know what size my lines are at the master cyl, or what size I should use on the rear end etc etc. Also I want to change from the right side to the left going to the back and change the mounting braket to the flexable like to the rear end. Has Any one done this to there truck? Let me know.

Gerry