1994 Jeep Cherokee I have cruddy brakes.

Where did you get the Master Cylinder from it may be defective, Declan.

I know its not the cylinder because I put one that I know for a fact works, I'm thinking maybe there might still be some air in the lines even though I cant see any air coming out when I bleed them.

Are you getting a good stream from bleeding, Declan.

Yes, everything went fine when changing the parts and bleeding the system, i'm thinking there might be a air bubble in the system that just wont come out.

If you think there is air you will not get a steady stream of fluid, how does the brake booster work, Declan.

Did you get it sorted I have same problem, and have done everything you can think of replaced everything bleed everything and systems but still goes to the floor ! It all good then suddenly nothing and then they back!