Upper half drops.
 

Have noticed that the top drops about an inch after it has been raised for more than an hour. Does this indicate that the fluid level is low or is this normal. The only problem I have is that when it drops, the seal is not tight. Any info would be greatly appreceiated.:confused:

It is probably dropping because the manual valve is dirty or not tight, located on the lift motor. In the worst case the hydraulic cylinder seal could be leaking internally. Assuming that you have no external leaks. There is a post with pictures about this, if I can find I will post it.
Here is the link, I found it, it is in the Reference Library.
https://www.hilotrailerforum.com/f61/...o-trailer-129/