I got no brakes, the front ones when i bleed them only a little bit of fluid oozzes out. And the back brakes look like they have grease all over them.. (its not brake fluid)( looks like rear end oil gunked up?) what could be myproblem???????????????) my truck has new master cylinder, brake booster, both new calipers, and new brakes. the back brakes bleed out fine. a steady stream. no air. the front is terrible? what could it be????

 

I just did the brakes in my 2600 and bled the front brakes went to drive it and the front brakes would not lock up only rears found out there was still air in them even after spending most of the day bleeding them just worked my way down the lines not to mention the front lines were bad and one caliper was sticky

 

It is possible to get a poorly rebuilt master cylinder. In this case it will not build any hydraulic pressure. I always prefer to go new on brake parts. Did you also replace the wheel cylinders on the rear? If you are getting gear oil on your rear brakes, it means that your axle seals are leaking.