How is it going guys, I'm just dropping in to report an update. I got time this weekend to complete my brake line repair.

Backstory:
The truck had a rusted out main rear feed brake line. It finally gave out a week ago and spilled most of the brake fluid on my trip back home. When I got home I noticed the brake line along with the fuel lines and wire harness trenched with brake fluid. This made it hard to spot the hole. The next day I topped off the reservoir and had my wife depress the brakes while the truck engine was off and voilą the line was squirting up into the under body and splashing all around.

Actual fix:
I disconnected the main OEM coupling right behind the driver side tire and the rear nut that connects to the brake hose. Two extra cuts with the diagonal cutters and bam I ripped the line out. Well sort of, the clips that hold the line are gripping the old line tight. Took some persuasion, but I got it done. Unfortunately, while under the truck, I noticed a smell of gas near the brake leak. My guess is the brakes have been dripping for some time now and accelerated the erosion on the fuel lines. So now my brake line problem is a fuel line problem too. I will post that repair in another post. I used a copper nickle brake line 3/8" x 10ft long to replace the old line. I used the rental tool at Autozone to make the double flare on either end. First I made the flare on the end near the engine. I then shoved the line best I could to follow the OEM path rear to front. I was then able to make a closer judgment on the exact length required. I freestyled the bends and curves best to mimic the OEM path. After double-checking, the line was positioned correctly and in clips. I made a mark at the 2nd cut point and used a midget tube cutter to cut the excess. Had to double flare the second end while laying flat under the truck, but it wasn't too bad. The final bend was an almost 90 turn down to the flex hose. I used the traditional pipe bender here. I connected the line and snug up both ends ⅝ flare and new line used smaller 9/16 flare. After topping off the brake fluid, I checked for leaks. Besides the massive fuel geyser, I had a small dripped on front coupler but a quick re-tighten fixed that.

Post fix:
Bleeding the system was not as straight forward as I presumed. I used a brake bleed wrench with a check valve to make the procedure a one-man operation. After following bleed order, I was not getting maxim firmness on the pedal. I concluded my tool was faulty and somehow allowing to are back in through the bleed valves. I had to then resort to the two-person method. This method resulted in better stiffness of brakes before engine start. However, once the blazer was turned on the pedal seemed to get spongy once again.

Conclusion:
I'm going to assume there is some air in the ABS system. I did not have my bidirectional tool with me so I figured I would test the brakes out anyway. The brakes are functional and seem to be as before however I was never satisfied with that trucks level of brake pedal firmness. Knowing I have to replace the front left caliper and front brake pads. I opted to buy a pressure brake kit and get my bidirectional tool back. I will report back on my new results after brakes are replaced.

 

Great write up.

I'll be super interested in your results with a pressure bleeder combined with the bidirectional tool to activate the ABS system.

 

Update!
I was unable to locate my bidirectional tool. So I decided to proceed with the pressure test. I pumped the system with 10psi and I It was dropping ever so slowly. Nonetheless, I found that I had a pinhole leak in the front driver side brake line . I was tucked away under a flap and there were no drips or signs of leak until I applied 10lbs of pressure in the system. I presume that's why I was not getting a firm brake feel. I ordered my 3/16 line and fittings. I will update once the new brake line is installed.

 

Update!
Ok so I ripped the old lines out and formed new lines. I had to do both front lines after all. One was leaking, and the other had an illegal compression fitting, I was there and had all the tools ready, so I went ahead and replaced both. After install, I checked for leaks and found the psi to stay stable. I went ahead and bleed the entire system several times with the pressure kit. I ended up with a pedal hard as a rock. Mounted the tires and took the truck for a road test. It ran well but on the first hard brake that engaged the ABS the pedal sponge feel came back. By the time I was back home, the pedal was real sponge again. No leaks under the truck and brake fluid still at max line. My next step is to get a directional tool and attempt an ABS purge.