Brake Problems

I have replaced rotors,drums, pads, shoes. I have ran 2 quarts of brake fluid thru system, old fluid has a yellow color to it. Master cylinder has a green slime in it which is problably causing the yellow color. When I bleed the system all is good for a day or two then ther is a bad vibration in LF and RR. Do you think I need to replace the master cylinder to fix this problem? Could it be ABS sensor? Open to any ideas.

Are you loosing brake fluid?

LF and RR operate off the same line into the master cylinder. I think with the green slime you would do well to replace the master cylinder.

If Your establishing new life forms, besides being particle contaminated, your running w/ a high moisture content. Remember science class? H2O @ 212F = Vapor! You might luck out on the master but their not that much $. You don't seem like you want to deal w/ your brake system alot, so do yourself a favor & switch to synthetic Fluid, because Your RABS valve is next & that's when the fun really starts. Synthetic might buy you some more time.