In Reply to: maintenance posted by doug on October 12, 2017 at 13:12:26:
At the top of the forum page, click on "How To's" in the red bar.
Scroll down to the section on HYDRAULICS, where you will find several articles relating to the hydraulics of your 8N and NAA.
JMOR's excellent diagram is there as well as some info from Zane Sherman & Tim Daley.
Reading the text, while relating to the drawings, should help you find the info you need to make repairs.