I recently was made aware how easy it is to bend 3/8" SS tubing...a flare kit, a tube bender, and like 30$ for 20' fo 3/8" SS from summit and it doesn't seem like too much trouble.

IS there anything special to redoing brake lines? Would I gain anything (Other then the fact I could route it how I wished)?

 

unless your brake lines are rusting through causeing brake fluid to leak there are no gains except for what you mentioned, being able to route where you want to go. Just one question......What's wrong with the current route the brake lines are taking?? If clean brake lines is your only concern just disconnect the flex lines from the hard lines and flush the hard lines with a can of brake cleaner. If your looking for added stopping performance your looking in the wrong place. Try going for the dual piston calipers with larger rotors or swapping those rear drums for disc.

 

If re-doing the brake lines does nothing for you, then what's the point of those stainless steel lines with the red/blue fittings....??

 

Those are brake hoses, he's talking about the hard lines.

 

yes that's true If you replace the flex lines with braided lines they will increase decrease your stoping distance because they flex less when pressure is aplied to the brakes. But he's refering to redoing the hard lines that run from the MC and under the car

 

Most flare kits don't want to flare stainless tubing because it is so hard. I've broken four of the 3/16" madrels doing it in the past. The typical Sears, NAPA, and other flare kits aren't up to the task, so I'd be sure to buy a good flare kit from Classic Tube or Inline Tube that can handle the stainless tubing if you decided to do it.

 

the best choice for stainless is a hydraulic flare kit. But they run around $300

 

Someone told me to get a flare kit from a refrigeration suppy store, that the ones they use are better.

For one thing, the brake line has like an expansion loop that runs in front of my wonder bar I believe. Plus there is brake line UNDER the oil pan on the K-member. While I'm at it I could probably make my own transmission lines, because I do NOT like where they run, they make it so I have to drop my ypipe to get my starter on and off.

 

are you sure you want to use 3/8" tubing for brake lines? seems kinda big.

 

Yeah, now that I think about it brake line is usually 3/16", not 3/8". You won't have the right pressure with line that big.

 

How would the size of the line make a difference to the pressure?

 

For a given volume of liquid the size of the vessel (in this case the brake line volume) determines the output pressure for a given input pressure.

When you step on the pedal you initiate the braking cycle by introducing the force of your foot to the piston inside the master cylinder. This forces brake fluid through the master cylinder and into the braking system. The brake lines are sized so that a certain amount fo pressure will reach the calipers or wheel cylinders. If less than the designed amount reaches these components brake performance will be bad, and stopping could be very scary.

Essentially if fluid flows out of a 3/16" passage into a 3/8" line the pressure can't be maintained, because the volume increase will create a pressure drop. It is meant to go from 3/16" to 3/16" to maintain system pressure.

On a side note, and one that is actually important to what the initiator is trying to do, is that the flare seats in all brake components are designed for 3/16" line, and 3/8" won't fit.

 

Just for clarification, those brake hoses that people replace with braided stainless steal ones... are those the short rubber hoses that go from the harder metal break line to the calipers? (that are less than 2 feet long?)

Thanks

 

Yup!

 

but the fluid isnt moving between the 2 lines... both areas are full, and the master cyl just displaces a specific amount... then the force is transfered thru the fluid and the volume remains constant by having the pistons by the calipers move out.


the lines could be 3ft for all we care.... while a pressure drop occurs like you say when a fluid is FLOWING thru a object, brake fluid doesnt flow.

 

The pressure issue really isn't linked to fluid "flowing". That was a bad choice of words. Obviously the fluid doesn't really flow, because there is no air in the system.

The pressure is affected because in essence there is a change in the surface area in the middle of the column of fluid that is moving through the brake line. Pressure is simply a measurement of force applied over a given surface area (psi - pounds per square inch). When the surface area is increased the pressure drops if the force remains constant.

 

You don't quite have that right. The pressure inside a closed hydraulic system is essentially uniform through the entire system, regardless of the size of the lines. A difference in pressure anywhere would cause a net flow of fluid.

 

There is no pressure differential inside the braking system, because it isn't under static pressure. There is no pressure in the system until you apply foot pressure to the pedal. Once you do the pressure generated is directly linked to the size of the passages through which the fluid transfers the force from your foot. The line size is definately important. If you don't believe this try adapting a section of 5/8" hard line between the master cylinder and the wheel cylinder or caliper. Take pressure readings at the caliper or wheel cylinder before and after and see what happens. The system with the oversized line won't break 800 psi, and you need about 1,200-1,500 to stop a car properly. Effectively what you are doing is putting a reservoir in the middle of the line, so that the force generated at the master cylinder is disipated throughout the reservoir, and fails to reach the wheel cylinder or caliper.

 

Just buy new lines that are already bent:

www.inlinetube.com

www.finelinesinc.com


Ed

 

Couldn't agree with you more.

Classic Tube is another good source.

 

That looped line is your power steering line, it acts as a cooler.