Ever since I've owned my truck, the brakes haven't been all that awesome. They felt spongy, and generally sucked. After a while both the ABS and "Brake" lights would come on and stay on. I bled them, I changed the master cylinder, put all new hardware in the drums, even swapped the rear to disc's, and never could get them to perform like I thought they should, but eventually gave into the thought that they were 1991 dodge brakes, and that was that.
After loosing my VSS circuit on a road trip, having the odometer, speedometer, cruise control, and overdrive all stop working, I was attempting to diagnose that. In doing so, I jacked the rear of the truck up, and put it in drive to spin the rear driveshaft and verify that the speedo gear was turning. This worked well, until I went to stop the tires from turning. I hit the brakes, and the tires didn't even slow down. This identified to me that my rear brake circuit was completely not working.
Some research, and given my symptoms, ABS and "BRAKE" light on, non-fuctioning rear brakes, and I agreed with the internet commando's that my Rear Anti-Lock actuator (sometimes refereed to in internet land as the RAWL or Rear ABS module) needed to be replaced or bypassed.
Reading the forums, you HAVE to go to NAPA and get part numbers:
7917 and 7828
So, I went and got them. Something like $10 for the fittings, and an $8 quart size jug of brake fluid later and I was on my way.
The bin they are located in behind the counter refers to them as Master Cylinder adapters.
So I got home, and looked under the truck, and found the ABS module / RAWL on the drivers side frame rail, approximately above the rear axle.
Some staring at the Napa fittings, and I determined that the internet was, infact, right.
The line headed into the back of the RAWL has the 5/16" brake line fitting on it. You could unbolt the brake line that runs from the master cylinder from the RAWL, and screw the 7917 fitting on to that, then the 7828 fitting onto the 7917 fitting, then bend the line back forward, and install it (with the adapters) into the top of the rubber brake line that goes to the axle.