Your lucky today,
My crystal ball that tells me what you are working on,
is slightly clearer than mud.
So I am assuming you might be working on
a Sunstrand 15 series hydro, if so,
you can replace
3 out of the 4 seals.
Input charge pump,
output shaft,
and the trunion shaft opposite the actuation lever/springs, without taking the hydro apart.
