Has anyone replaced the brake lines - massive leak - 99 Z28

[Neil]

My brakes were acting like there was air in the line, but would not hold pressure even after pumping. There was not fluid on the ground (that I could see) and the brake pads were all about 1/2 worn, still plenty left.
I suspected the brake master cylinder was bad so I replaced it with a new one. I got in to test the new brake master cylinder and pumped the brake and it initial held pressure, then started doing the same thing. But this time I heard a little hissing noise ever time I pumped the brakes. My son had been helping with the master cylinder and I asked him to find where the hissing noise was coming from. I had the car on jack stands and the wheels off already from inspecting the pads. I pumped a little more and the rear brake line blew out. The brake line sprung a massive leak right in the center of the car. The lines are all rusted and corroded. I need to replace at least the two rear lines, and while I'm at it I may as well replace the front line. (NOTE: These are the solid metal lines that run from the ABS module to the rubber hose at eash wheel that runs to the caliper. Not the brake hose.)

Has anyone done this? Did you get pre-bent lines or make them yourself? How hard is it?

Thanks - I appreciate any input.

[pajeff02]

Replacing brake lines isn't too bad on any vehicle, depending upon access and the ability to get the fittings to unscrew without destroying them. You'll need a set of quality line wrenches, a decent brake tube bender, and patience. Pre-bent lines can be obtained from vendors and are certainly the easier, but more costly, route. A Mity-Vac makes short work of bleeding brake lines and is highly recommended. I always perform a final pump bleed though just to ensure that all the air is out. While you are at it, upgrading to stainless flex hoses is also a great idea and will help firm up your brake pedal feel, plus the stock rubber lines are getting up in years at this point and should probably be replaced anyway.

[oldmanZ28]

^^^ that.
To OP,you didn't mention if your car is 3 channel ABS (one line to the rear) or 4 channel ABS & TC ( two lines to the rear).
I did a similar situation on mine this year. Replaced master cylinder (leaking at rear of master cylinder),test drive blew the hard line (rust) a few inches before it connects to the hose for going to the rear end. I made the project very specialized. I didn't care to work with the 'bubble flares' going to the caliper hoses (10.0 x 1.0 fitting) and going to the hose for the rear end (12.0 x 1.0 fitting) and the tiny inverted flare fittings(3/8-24) at the tee on top of the rear end. I cut the line in the tunnel at where it was still good and converted all the hard lines rearward of that to -3 AN. Also used 3/16 stainless steel tubing for the replacement hard lines. Someday I'll replace the hoses with SS hoses and start converting the front lines too.

Here's my thread from on ls1tech
https://ls1tech.com/forums/suspensio...ings-info.html

[Neil]

I think it is 4 channel - I have two brake lines (steel) running form the ABS to the rear of the car. Running next to the fuel line down the center of the undercarriage. Is it common to just replace the section of the line that is rusted? That would be way easier.

[oldmanZ28]

2 brake lines to the rear is 4 channel. I only replaced the rusted area. You'll have to cut for a splice and then determine if you cut far enough forward to determine if the existing tubing at the cut is good enough,you might have to cut more depending on your determination. Since that line goes rearward to a body mounted bracket for the hose end of the hose(s) that go to the rear end,you might/probably run into disassembly problems of the fitting that goes into the hose end. Since I work on rear ends,I had a few that I was able to get a usable hose off of. I ran into so many disassembly problems,I removed everything and converted over to -3 AN.