Hello all.
I am doing a favor for my g/f's grandpa, trying to fix his brake problem, but having no luck. The problem was the brake pedal is going all the way to the floor. I have replaced both rear wheel cylinders, both shoe adjusters, new rear lines, master cylinder and checked the whole system for leaks. I adjusted the shoes out and I bled out about a 20 oz. of fluid with no difference at all. Is there anything I am missing? Any tips or tricks?

91 Cherokee 4.0 no ABS

 

Sounds like a bad master cylinder. If it is bad then no amount of bleeding the system will help.

 

replaced already

 

Check Wheel cyclinders. Had the same issue. had a small leak then adjusted rear shoes out a hair

 

is there a method to adjusting the rear shoes? The self adjusters are no longer usable. I just spun the wheel and adjusted them out until they grabbed and then backed of a couple turns? is this not right?

 

Did you bleed all 4 corners and did you bleed the master cylinder before installing... any air trapped in there can cause a bad pedal... And of course, don't rule out a defective master cylinder... not that common but it can happen... I would bleed the master again and then the rest of the system... as for your adjustment on the rear shoes, not sure what a couple of turns means. Found this:
Qouted from Automedia.com
"Now, you're ready to adjust. By all means, use the slot in the backing plate or in the drum itself to insert your adjusting tool through, so you can make the adjustment with the drum on. If no slot, you'll have to keep removing and installing the drum during the adjustment procedure, until you get it right. Keep increasing adjustment until there is a slight drag on the drum. Tugging on the parking brake cable during this procedure will "center" the shoes, so you can get a more accurate adjustment."

 

you're sure the problem isn't with the front?
as mentioned, you may need to bleed the master before you bleed the wheels. then start with the furthest wheel from the master, finishing with the closest.
have someone pump the brakes while you give the bleeder a quick crack. try to close it before the pedal will hit the floor. you may have to repeat each bleeder a number of times, but i find this way the best.