First off. I am taking it in to be looked at. I just want to hear what other people may have to think.
This started when it got super cold then warm and super cold again last week. It feels like I have no assistance from the brake booster but my brakes are still working for the most part. I have to stand on them and they work. No pressure bleed off or leaks as far as I can tell. just a lot of work to stop. I cracked my brake res to look at the fluid and this is what I saw. I've already tried flushing the system. The right side it fresh clean fluid. I sucked out and wiped out all the crap I could from both sides and the left returned to that black color. I got the front flush and bled but I couldn't break the bleeders loose on the back so that's when I gave up and decided to take it in to be looked at. I've done some reading and people suggest everything from a flush to a bad seal or water in the booster. Not sure how I would go about testing the last one without just buying a new one.
I couldn't bleed the backs as I couldn't get the bleeder to brake loose. They were seized with rust. But I'm concerned it's more than just needing flushed because it only happens below freezing.
DOT3 brake fluid absorbs the humidity/water from the air. It is one thing that causes the discoloration of the fluid. Why it is recommended to completely replace brake fluid every x amount of miles and years.
From what your describing it could be the combination of very old contaminated fluid, and air in the lines. A shot of PB Blast on the bleeder screws over a couple of days will help them to break loose. If not, use a big pair of vise grips and have new bleeder screws to replace the old ones with. Then bleed and try
Run the engine, shut it off. Depress the brake pedal a few times. How many pumps do you get before the pedal goes rock hard? If the answer is 0, your booster is shot/leaking.
You didn't let the reservoir go empty while you were bleeding, did you? Because the symptoms you describe makes it sound like you have air in the lines. It doesn't explain the black gunk, but it would explain the hard pedal.
1995 YJ, 5spd, Forest Green, 4.0L, off road package, soft top, 230k miles and counting
Took it to the shop and my rears brakes on both rides where shot. Paid way to much to have them replace the whole rear setup.
Also they thought that braking both handles on my driver's side door would make for a great bonus. Door wouldn't open so it seems they just keep on ripping on either handle. Didn't even both to tell me about it... My door doesn't like to unlock sometimes so that's why the interior panel is off. ****ing ****s.