dakota breaks

87 dacota no presure at the master sylinder when i bleed it ? i have put 2 new ones on and no different. i have oil at all breaks but no preshure.

Put it on a vise with the two plastic hoses that come with a rebuilt cylinder hooked up. Use a rod and press in the plunger until it is pumping fluid. This recirculates it back to the reservoir. I've gotten defective ones before but never 3 in a row.
I think you have air in the unit.