I don't have any back brake pressure. I tried to bleed but no fluid coming out. Would this be a master cylinder problem?

 

Sorry didn't specify 92 Dakota drum brakes

 

Could be rotted brake line or bad WC.

 

Check the rear lines for leaks and remove the drums and check the WC's

 

yea, i would say check the lines for kinks and stuff, and if you have good pressure up front and none in the back i would check the proportioning(yes that is spelled right, i even googled it to make sure) valve, that is what splits everything back to front

 

It's also possible that the rear brakes are warn need adjusting

 

I had the same problem on my 92...i let both of my rear drums bleed at the same time until i saw fluid coming out and they basically bleed themselves out and then i tighten the bleeders back up and add fluid...thats how i got mine to work you might give it a try