'95 Cherokee XJ SE with ABS that hasn't worked in years. Light is on. This rig had only 9000 mile put on it in the past 14 years, so obviously, it sat a lot.

The left front caliper was not releasing, so replaced the caliper and put new pads on both sides of the front Bled the side that got the new caliper. Brakes seemed pretty good.

Had a little too much pedal travel, (firm, but low) so decided to check some things. Jacked up the vehicle, started it, put in gear, and the wheels turned slowly. I hit the brakes and THE REAR WHEELS KEPT TURNING. Decided to a
adjust up rear brakes. Drivers side turned too easy, auto adjuster wasn't against the adjuster wheel, so I pulled the drum to inspect. Front shoe was worn out, rear shoe was still thick.

I very lightly pushed the brake pedal with the drum off and noticed only the front shoe moved, so new shoes and new wheel cylinder. When I got ready to bleed the driver side, I had very low fluid pressure. Wife was doing the pedal work so I thought she wasn't pushing very hard. Got the air out and put the wheel back on. Still hadn't touched the passenger side other than adjusting.

Since both rear wheels were up, I started it up and put it in gear. Wheels got up to about 5 mph, I pushed the brake and the rear wheels kept turning again. I stood on the brake and got them to stop, but unless I kept HEAVY pressure on the pedal, the wheels started turning again. Had wife assist again and told her to really stand on the pedal. I open the bleeder and get a very weak stream, just barely more than a dribble.

So, Is it;

1. Proportioning valve?
2. Improperly bled ABS system?
3. Master cylinder?
4. ????

No bends or kinks I can see in the rear brake line from the front to the rear.