You need the rest of the manual. The manual comes in chunks. Each chunk
is a PDF that contains only a few pages. This is done to keep the file
sizes down so you don't have to wait ages and ages to download a single
gigantic file just to have a peek at one particular thing.

Click on the ">" arrow at upper right of each successive page until the
next page takes a lot longer to load than the others did. At that point
you're into the next PDF and can do a "Save As" again. You may end up
with ten or more PDF files for the whole manual. Save them all into the
same folder on your computer and they should act as though they were one
single file.

But if you're only looking for ONE specific thing online -- such as the
Maintenance Schedule -- all you need to do is start at the Table of
Contents, and click your way to that thing. I often find it quicker to
go directly to the Index (usually at the very bottom of the Contents),
then to the letter I want ("M" for Maintenance), then to that specific
item. Once you have that specific item up, you can do a "Save As", and
you'll end up with the PDF which contains that item plus a few other
pages.