What is the condition of the front system?
How are the pads? How are the rotors? Are both sides of the calipers working properly(they are four piston units, pads should be evenly worn)
Have you tried bleeding the system again, especially the front? The front can be difficult to get all the air out of some times...
Have you removed the rear drums and visually inspected the wheel cylinders for leaks? I would first look at the rear cylinders if you have not, and make sure that they are not leaking. Just becasue you do not see brake fluid on the shoes, cylinders or backing plates does not mean that they are not leaking. After the drum is off, take a pic or small blade screwdriver, and where the rubber seal meets the cylinder, seperate that in a small area, and make sure that it is dry inside that area, as if there is fluid in there, then it is getting past the seal in the wheel cylinder. Please wear saftey glasses when doing this, as if there is break fluid present, and the rubber cap snaps back down, you could end up with it in your eyes, like this dumb ass did once...
Good luck!
-Steve
