when you do the dual diaphram swap, do you need to upgrade the master cylinder as well or can the old one still be used?

 

bump

 

So this is my first post, i spent weeks looking for my XJ, finally got one and brought her home, spent the last 4 days working on it getting it right, and this am decided to start on the brakes, saw the weird system and looked up info to find out what was going on and found this thread, any come up with exactly what to do yet? i was planning on selling my camaro to lift my jeep and maybe help pay for tires, but looks like i may be in brakes heck now. any help would be greatly appriciated.

 

Spent all day with these brakes. Just bought it (90 Cherokee with abs partly converted) with a booster and master cylinder from who knows what. I have a leak on the master cylinder. Wrong thread? Things are starting to make sense now. Brakes are still way hard. You're saying change out the proportioning valve with a non ABS unit? Still has this disconnected brake line on the firewall with that "danger" tag attached. Found a 4 prong connector, plugged it in and it scared hell out of me with some kind of rattle. Do I still have a chance to make things work old school? I'll try and retrace the origin of the present booster and cylinder. Sure hate to run into an emergency stop situation in this condition. Anyway the Laredo is in great shape It's all electric and works great save for the brakes. Price was right.

Bled all 4 corners twice, tightened the adjusters on the back brakes, went through procedure for leak in booster. There is still a lot of free pedal but the Jeep stops without pulling. No matter how hard I push the brakes won't lock up. Whoever converted it to standard single diaphragm booster did a good job. I didn't know about the ABS stuff. The pedal is easy to a point then gets hard to push. Any ideas?

 

Pictures of booster ? As for the leak 90 was ase thread newer masters are metric...

 

Is it cheaper to fix the system I already have or convert it to a different system? I have no brakes what so every. They went out on me completely.