It's typical for these aging cars to have components that are either barely functioning or practically turning to dust. Case in point, the factory brake lines found on our project El Camino were in no condition to use. While a portion of the rear brake lines were present, the lines to the front were completely missing. Additionally, the lines that were left behind had been rusted through and the end-fittings were completely unusable.
Several months ago, we replaced the entire brake system with one from Master Power Brakes ("Brakes In A Box", page 40). It came with new 11-inch discs up front and a rear drum assembly with a power booster and master cylinder. What we didn't show you until now is that we never replaced the brake lines. Since the rear lines were in no condition to function properly and we were missing the front lines, it was obvious we needed a complete kit down the road.
The good news is that our search for new lines was an easy one by simply calling Inline Tube. If you weren't aware, Inline Tube specializes in factory-correct OEM or stainless lines for nearly any application you can think of. Their kits are manufactured with a CNC-bender and computer cut to ensure a guaranteed fit. If new brake lines are what you need, Inline is sure to stock them. While Inline Tube offers the standard OEM lines which would have sufficed, we upgraded to the stainless kit for a few extra bucks to resist potential corrosion. Our kit came with everything we needed, including nine stainless pre-bent brake lines, all of the necessary clips, unions, and a new rubber line that runs over the rearend to feed fluid to the rear brake lines
Unfortunately we were unable...
Unfortunately we were unable to remove most of the old lines by loosening the hardware. We ended up cutting most of the rear lines away with a set of wire cutters. This saved us time since we weren't going to be using any of the old hardware with the new stainless kit.
If you're worried about this job being a bit overwhelming and difficult to tackle; don't be because in reality, it's rather quite simple. Take it from us; while it's always a good idea to have the original components to guide you, we unfortunately didn't have that luxury. It's straightforward though and a little common sense can go a long way.
We started at the rear of the El Camino and worked our way forward to the master cylinder. Space is tight under the car, so any way of getting the car up will help when installing the new lines. It's also a good idea to start by laying out the each line underneath the chassis to help get a better visualization of where each line needs to be installed. All said and done, we only spent a couple of hours removing the old lines and running the new stainless kit, so follow along as we show you how to get the job done.
Quick Notes
What We Did
Replace the entire factory brake lines front to back with a stainless kit from Inline Tube
Bottom Line
No need to worry about stopping pressure

Using a 1/2-inch socket we...

Using a 1/2-inch socket we removed the rearend cover bolt which fastened the rear brake line union bracket to the rearend.

Fortunately it was easy for...

Fortunately it was easy for us to determine which lines attached to the rearend housing. Out of the box, they were zip-tied together and it was only a matter of threading the fitting of each line into the rear of the drum brake housing. For now, we left the fittings handtight.

We used the original T-union...

We used the original T-union bracket that attaches itself to the rearend cover and mocked up the new rubber line, bracket, and T-union. We tightened the T-union to the rubber line with a 5/8-inch wrench and a set of pliers. We then placed the bracket and rubber line above the rearend. We ran the rubber line through the rear crossmember. Again, we left the whole assembly loose for now.

Next, we threaded the remaining...

Next, we threaded the remaining ends of the rear brake lines into the T-union handtight. Next, we positioned the bracket and threaded in the rearend cover bolt into place and locked it down. We tightened up the bracket with a 1/2-inch socket. From there, we placed the supplied clips to the lines. The clips prevent the line from backing out of the bracket.

We continued our path towards...

We continued our path towards the front by fishing the rubber line through the rear crossmember. Next, we took the longest of the stainless brake lines and fed that to meet up with the rear rubber line. We threaded in the stainless line handtight and placed the clip to hold the assembly tight.

Moving forward, we attached...

Moving forward, we attached the stainless brake line to each of the factory clips along the framerail to hold the line in place. Eventually, we made it to the front of the El Camino. From there, it was a matter of piecing the rest of the lines to their appropriate spots.

The only "arch-shaped" line...

The only "arch-shaped" line in the kit is destined to feed brake fluid from the master cylinder to the front passenger side caliper. We placed that stainless line across the member and threaded its end into the rubber line coming from the disc brakes.

Our Master Power brake kit...

Our Master Power brake kit is used on numerous applications. During our original install, we placed the proportioning valve under the master cylinder. However, in order for the Inline Tube kit to fit properly, we used their supplied bracket to relocate the valve to the fender side of the master cylinder.

The opposite end of the crossmember...

The opposite end of the crossmember line will connect with the supplied 90-degree union and then to the stainless brake line coming off of the proportioning valve. Our MP conversion kit proportioning valve supplies brake fluid to the passenger side of the car from the bottom of the valve. We threaded in this line there handtight.

What was left? Included with...

What was left? Included with the Inline Tube kit are two very short stainless lines. These lines feed brake fluid from the master cylinder to the proportioning valve. The bigger line (1/4-inch) will feed the rear brakes while the smaller, 3/8-inch line provides fluid for the front. At the top and end (facing diagonally) of our Master Power proportioning valve (pointing towards front bumper) there is another threaded opening. Here, we threaded in the smaller line for the driver side front brakes handtight.

For final fitment, we then...

For final fitment, we then went along and tightened up each fitting with a 3/8-inch wrench.