Huge file size EPS / PDF / Print PDF

Hi, we are having trouble saving our product drawings as eps-files lately.
A pdf from Creo Parametrics is 900 kb, i open it, add some arrows and numbers and a white filling and save it as 
eps - 11MB
ai - 6 MB
pdf - 2 MB

if i choose "print as pdf" it goes down to 900 kb again.
We would love to save those pictures as eps but our manuals just get too big in that way..
Is there any way to keep down the eps-filesize?

Thansk for your help,
Verena