Brakes.....

87 xj d44 4.0 aw4 np231
I searched, there were 95 brake threads. One more won't hurt, will it? I've had problems with my jeep having real soft brakes since I bought it 1 year ago. I replaced all the pads, and had the system bled. Lately i've had no firmness when pressing the brake pedal. The jeep still stops, and is drivable, but it doesn't get power until the pedal is near the floor. My xj recently started pissing out the brake fluid from the rear left wheel cylinder. The rod on the wheel cylinder that forks onto the pad was not catching. I then disassembled the brake assembly and corrected the problem. Then I refilled the master cylinder with DOT 3. I turn on my jeep, and amazingly there's compression. The brake pedal feels nice and firm. I took it for a drive and the brakes felt great, nice and firm. It felt uncomparable to what I have had before. There was plenty of stopping power for my 31's. Then my brake fluid started leaking again. I replaced the seals, the spring and the rubbers inside the wheel cylinder today. I refilled my MC again. I was really hoping this would give me that firm feeling, but it didn't. I solved the issue with the leak, but I still have that soft pedal. From all 56 threads i've read, i'm guessing it needs to be bled. What I really want to how I got that firm feeling in my pedal. I didn't bleed it, I just fixed that forking mechanism. Someone must know.

Do a gravity bleed on your cylinders. Starting with the longest line (right rear) get a short hose, put on end of bleeder with other end in a catch basin. Open the bleeder a couple of turns.

Take the cap off the master cylinder and make sure it full. I would give it at least 15 minutes. Repeat with LR then RF then LF. The fronts you could probably cut the time in half.

I do this every 6 mos and it keeps the water out of my lines.

I won't guarantee it will give you that firm feeling because there may be other issues involved, but it will be a step in the right direction.

You need to take a closer look at the unit hub, to check it right the caliper needs to be off.

Make sure your brake lines are good, brake lines that stretch make the brakes feel soft.

ABS or non? Have you looked into doing a dual diaphragm booster swap from a 96 (or 95?) - 01? I was able to scrounge up the parts at a yard a while go and just did the swap and it was much more painless than i had expected. Very nice--the tightest pedal i have ever felt and the best breaking of pretty much anything i've driven. if you have some $ to spare i'd look into it. www.madxj.com has a great writeup on it

uvaldetxj said:

87 xj d44 4.0 aw4 np231

My xj recently started pissing out the brake fluid from the rear left wheel cylinder. The rod on the wheel cylinder that forks onto the pad was not catching. I then disassembled the brake assembly and corrected the problem.

I solved the issue with the leak, but I still have that soft pedal. From all 56 threads i've read, i'm guessing it needs to be bled.

Click to expand...

Ok for starters You fixed the fork on the wheel cylinder. You did NOT bleed the system, but fluid was running out prior to repair. You need to BLEED the system... This is how you get the Firm pedal back that you spoke about...
Good luck....

Leaking wheel cylinders are a sign they are in need of REPLACMENT, not just "reassembly". They are leaking becuase the old brake fluid attracted moisture that cause the cylinder walls to RUST. A rusty wheel cylinder cannot seal properly regardless of the condition of the seals themselves.

Replace BOTH rear wheel cylinders, flush and bleed the ENTIRE brake system, and you will probably be good to go.

When you refer to "flushing" the brake system, is that the same as just bleeding it until all the old fluid has been replaced?

Good news. After fixing that leak, I got that firm feeling. How? I don't know. I bled my rear brakes yesterday, the difference is uncomparable. The brakes feel so much firmer than before. It got dark, so i'm holding off the fronts until my next day off. Thanks for all the input fellas.