Question about tying into existing brake lines

[JC1]

I'm in process of having to install new brake lines for the rear drums for the 97 Honda Civic.

Part of the issue is that the original lines were so rusty after 23 years, where I need to splice into the line for the rear, the lines appear to be coated in some sort of rubber, so the 3/16 line is thicker in that section. I guess that is to protect the lines.

Is there a safe way to remove that coating to create the flares and use the unions to join the old to new or should I just create a new line hard line all the way to the rear drums, and then spray the exposed parts inside the wheel well with rubberized undercoating?

 

[Rand]

if you use ni-copp it shouldnt rust.

 

[JC1]

Yes I will be using ni-copp on the new lines.

The problem is the existing lines are a total PITA to access etc. Getting the front part of the line out yesterday I just disconnected from the proportioning valve and tried to feed around the steering shaft etc. What a pain in the neck. I will have to figure out how to fish these lines around stuff easier. I will probably run all new lines and flare them on the vice as opposed to being underneath a car with very little room lying on my back.

 

[HangFire]

There is a correct way to do this.

The wrong way is a compression union. (Don't listen to youtube Scotty, who will get you killed.)

The right way is a 2-way union, where you cut, slip on a threaded nut, and flare the old line on one side, just like the new side.

There is a caveat with using unions. They are heavy. You will need to support the brake line on both sides, and ideally, the union itself. If you leave it hang in the middle of a long run, weight and vibration will work against you and it will sag. For that reason many do not recommend it.

 

[mk378]

Going end to end is definitely worth it. Realize it isn't necessary to take the same route where they put the line on first before the rest of the car. You can go around the obstructions rather than have it high and tight against the firewall. Try to support the line as much as possible.

I did do it the long way on my Civic, remove the subframe and lower the steering rack. Then the old line comes out, use it as a template to bend a new one. This is the hard way.