This page over at etrailer.com has many articles and videos on all aspects of trailer suspensions, brakes, and much, much more. The section on Trailer Information in the lower left side of the page is where you want to look.
http://www.etrailer.com/info.aspx
For anyone who wants to become familiar with trailer systems, this is the place to do some learning.
Let me emphasize that many systems on our TT's are identical (or nearly) to the systems on utility trailers, horse trailers, etc. etc.
__________________
'11 Cougar 326MKS loaded with mods
'12 Ford F250 SuperCab 6.7 PowerStroke Diesel
Amateur Radio: KD2IAT (146.520)
GMRS: WQPG808 (462.675 TPL 141.3)