81 300sd how do you know which power steering seals for pump in part store.

[ibenz]

i see three different sizes for the front seal, is there a difference in the pump itself by brand or do i need to pull it to find out what size? this is in the peach parts store

[Stretch]

There are at least three different types for the Vickers pumps and then there are the ZF pumps too...

...I think you need to find a supplier who can check for the correct part via your VIN. That's what I did for mine - I went to the dealer. So the answer could be to contact this site's sponsors.