In the case of power steering and automatic transmissions leaks are often solved by reconditioning the seals with additives.
An old trick with power steering was to throw some brake fluid into the system. brake fluid puckers seals designed for normals oils and would either soften or swell the seals enough for amazing recovery.
I tend to believe that once you start treating systems this way instead of properly fixing the problem, you have given up on the car. Sorta like sending gramps to the old folks home.
In the case of the front motor leak it is not due to seal resiliance but do to shrinkage and gaps.
Bosch Master, ASE Master, L1
33 years MB technician