I assume you mean the awning rail that runs all the way front front to back following the joint line between the caravans side wall and roof?
If that's the case, and thats what you say has been "bodged" with silicone then you are wise to ask the question.
Clearly there has been some sort of "issue" at that location. It could be a water leak, or it could be that a fixing (or two) has failed. Either way it's sensible to investigate it sooner rather than later.
Removing and resealing the awning rail isn't the easiest of jobs. Mainly because it's never meant to need doing from new.
First thing I would be inclined to do would be to check inside your caravan where the sealer is present on the outside for any signs of damp and/or damage/rot. (What is the make model and age of your caravan as that can influence what you need to do)
If you do decide to removethe awning rail in its entirety firstly be very aware that it is easily bent, and if bent is a pig to get straight again !
The awning rail will be held in place by numerous screws AND sealant. The first task is to remove all of the screws. You will then need to cut through the sealant thats present.
Dental floss used like a cheese wire does the job quite well without a risk of scratching the caravan body.
It's not a job I have done myself, but I am sure someone on the forum has so will be able to offer suitable further advice.
Just a thought, but is this caravan a new purchase? If you bought from a dealer I would very strongly advise you to return to them and get them to do the job under guarantee. If they try and say its out of its 6 months or whatever warranty advise them that the fault was clearly present at the point you purchased it, so they are still required, by law, to put it right.
If a private purchase you have no comeback.
Hope that all helps.