I knew one of the rusty hard lines was going to go sometime, and even had a new one on the shelf (big one from front to rear), and just hadn't gotten around to it due to work/family. I'm in Ohio and the LC spent time in Chicago, she's rusty. All of the hardlines were a bit rusty, and I'd hoped to just go ahead and get all new hardlines and replace them all between Xmas and New Years, when I would be off work.
Sure enough, as soon as I swapped cars with my wife and she took the LC, the brake light came on the dash. She wiggled/released the parking brake to see if that fixed it. Then she just decided to keep driving and be cautious with the brakes (and never called me).
Well she made it around town and the 10 miles home, before telling me the light was on. I go out and wiggle the parking brake, nope. Look in the reservoir, and it appeared full at first due to staining. Opened the cap, and no, there was no fluid in there. Peak underneath, and lots of fluid dripping out the rear hardline near the diff. I had expected to blow at a rusty part along frame rail, but it actually blew in the part arched up in front of the rear axle. I poured some fluid in, and surprisingly you could still stop relatively fine, just a little spongy feel. No buzzer or other lights, and she thought the braking may have felt a little weak.
I ordered all the remaining pre-bent hardlines from the dealer, and it took a couple days to get them. $200 after taxes, not counting the big one I spent like $70 for a long time ago.
I was able to pour some more cheap fluid in and drive it into the garage, and still had some pressure. Eventually the loud buzzing/humming alarm came on, and so did the ABS light.
It looks like the rear brakes both share the same feed from the master cylinder, which is located near the top. If rears go, you should still have fronts for a while, which are most important. Eventually the lack of fluid in reservoir is probably not good, though.
Replacing all the hard lines was kind of a bear, and took me all day from 9am to 5pm. No need to drop gas tank or anything. Can access most fittings through wheel well, and there are like 4 fittings total above the rear diff which were very unpleasant. I soaked everything in ATF/acetone and PB Blaster days in advance. Still had to resort to vise grips to remove lots of the fittings. If you're in a rust-free climate it'd probably be much easier, but then you probably wouldn't be replacing hard lines then.
I bought new junctions for the front, but didn't use them. Old ones were rusty on the outside, but solid, and I knew if I tried to take out the bolt holding them to frame that the bolt would snap, and no good way to get a drill in there. Instead of trying to rig up zip ties to hold new junctions in place, I just left the old onces there.
At least I didn't snap off any brake bleeders, which might not have been touched in decades. Been there before. I bought a 'shake 'n break' 3/8" driver that fits in an air hammer, to hammer the hell out of rusty bleeders without snapping them. I also put a finishing nail in the center of bleeders to 'pin it' and prevent them from distorting while you turn them. I wasn't able to fit my air hammer tool in the rear for a straight shot, so I just used line wrench and hammer. The fronts were a bit gnarly, but the air hammer fit in there. I managed to beat the hell out of one bleeder a bit too much, but it got out, and I had to run to town for a replacement.
All is back together and has good pressure. I followed tips on 100 FAQ for bleeding, plus used a one man brake bleeder bottle. I just put the bottle on the ground and looked under the LC while I pumped brakes by hand. When bubbles stopped, I went over and closed bleeder. A couple rounds of that (including a quick drive and slamming on brakes on gravel to activate ABS), and she seems fine. No lights, no buzzers, holding fluid.
Sure enough, as soon as I swapped cars with my wife and she took the LC, the brake light came on the dash. She wiggled/released the parking brake to see if that fixed it. Then she just decided to keep driving and be cautious with the brakes (and never called me).
Well she made it around town and the 10 miles home, before telling me the light was on. I go out and wiggle the parking brake, nope. Look in the reservoir, and it appeared full at first due to staining. Opened the cap, and no, there was no fluid in there. Peak underneath, and lots of fluid dripping out the rear hardline near the diff. I had expected to blow at a rusty part along frame rail, but it actually blew in the part arched up in front of the rear axle. I poured some fluid in, and surprisingly you could still stop relatively fine, just a little spongy feel. No buzzer or other lights, and she thought the braking may have felt a little weak.
I ordered all the remaining pre-bent hardlines from the dealer, and it took a couple days to get them. $200 after taxes, not counting the big one I spent like $70 for a long time ago.
I was able to pour some more cheap fluid in and drive it into the garage, and still had some pressure. Eventually the loud buzzing/humming alarm came on, and so did the ABS light.
It looks like the rear brakes both share the same feed from the master cylinder, which is located near the top. If rears go, you should still have fronts for a while, which are most important. Eventually the lack of fluid in reservoir is probably not good, though.
Replacing all the hard lines was kind of a bear, and took me all day from 9am to 5pm. No need to drop gas tank or anything. Can access most fittings through wheel well, and there are like 4 fittings total above the rear diff which were very unpleasant. I soaked everything in ATF/acetone and PB Blaster days in advance. Still had to resort to vise grips to remove lots of the fittings. If you're in a rust-free climate it'd probably be much easier, but then you probably wouldn't be replacing hard lines then.
I bought new junctions for the front, but didn't use them. Old ones were rusty on the outside, but solid, and I knew if I tried to take out the bolt holding them to frame that the bolt would snap, and no good way to get a drill in there. Instead of trying to rig up zip ties to hold new junctions in place, I just left the old onces there.
At least I didn't snap off any brake bleeders, which might not have been touched in decades. Been there before. I bought a 'shake 'n break' 3/8" driver that fits in an air hammer, to hammer the hell out of rusty bleeders without snapping them. I also put a finishing nail in the center of bleeders to 'pin it' and prevent them from distorting while you turn them. I wasn't able to fit my air hammer tool in the rear for a straight shot, so I just used line wrench and hammer. The fronts were a bit gnarly, but the air hammer fit in there. I managed to beat the hell out of one bleeder a bit too much, but it got out, and I had to run to town for a replacement.
All is back together and has good pressure. I followed tips on 100 FAQ for bleeding, plus used a one man brake bleeder bottle. I just put the bottle on the ground and looked under the LC while I pumped brakes by hand. When bubbles stopped, I went over and closed bleeder. A couple rounds of that (including a quick drive and slamming on brakes on gravel to activate ABS), and she seems fine. No lights, no buzzers, holding fluid.
