E-manual
It's pretty difficult to know how to maintenance or repair a trike without a manual.
Fortunately, a very generous person has made many of them available online, at no additional cost to the viewer.
http://www.oscarmayer.net/atc/manuals/
It seems like this valuable resource is often forgotten or overlooked. The very first thing any new trike owner should acquire and still a great place to look first for current trike owners needing some info. It's always a good idea to have a paper version too, or at least print out pages needed at the moment.
If nothing else, save the site in your browser as a bookmark or put it in a favorite list.
The story of three wheels and a man...