I just recently replaced the powersteering pump on my 92 W250 diesel, and ever since then it keeps pushing the fluid out of the cap. I have bled the pressure line, and even let it run for an extended period of time (about an hour) with out the cap to cirulate the fluid. I have even tried turning the wheels back and forth with the cap off,and wathcing the fluid it seems extremely foamy. I'm out of ideas... you guys have any?