Mercedes 560SEL SLS quirks
 

hi everyone, My 89 560sel recently spring a leak in the hydraulic system. The level control was the culprit and has been replaced. So right now, I have a new level control and hydraulic fluid tank and lines with brand new fluid. I am not sure if My mechanic overfilled the tank but everytime I go on trips of more than 35 miles, the fluid overflows from the tank and leaks when parked and possibly when driving? my mechanic is stumped. Before I go out and evacuate fluid, what could be the problem? The ride is so smooth and very good. No harsh stiffness of any kind. I hear a thump going over bumps which could be the suspension airbags but those can be easily replaced. Anyone have any suggestions of solutions for me?