Go to the following web site and save the Factory Service Manual - "1983 Subaru EA81.pdf" file. Put the cursor on the link and click the right mouse button. In the menu that pops up, move the cursor to "Save Target As" and click the left mouse button. A window will open and you can select or make a folder to save it in on your pc.
http://jdmfsm.info/Auto/Japan/Subaru/--Old Models--/
There is a lot of stuff on that site. When you click on a folder and then want to go back, click on Parent Directory.
You mentioned brakes, they are in Chapter 10. It's a long document so the scroll bar will be small. Move it about half way down. The page numbers at the bottom of each page will be 10-1 etc.
I use Acrobat Reader DC to view pdf files. It's free.