Check with the Alaskan guys for things like the cylinders/rams for your camper...you need to know if they are the smaller/early or the fatter/late ones....don't mix them up. Send pics to them if you are in doubt. However....I would suggest that you install new O-rings first as that may solve your problem....as well as bleeding the system...but first of all, with the camper DOWN you need to fill the pump reservoir. A visual inspection may reveal cracks at the bottom of the cylinder and of course....oil all over the floor beneath it is a sign there is a leak!
Roof vent gaskets, Pirelli seal material (unless your is new, it probably needs replacing) and stainless steel screws to use when you put on new butyl strips under the eyebrows over the doors and windows and around the windows and vents and front/rear "J" trim.
You'll need to do some "Systems Evaluation" of the stove/oven and fridge/icebox and fresh water tank/lines/pump. Anything like fans or A/C will need to be evaluated as well and sorted out.
Welcome board...and if you spend some time reading through the Alaskan section in depth, you will find most of the problems and solutions you may incur.
Good Luck and happy camping!
Post the year of your Alaskan and a couple pics of any of the brass plates or other data plates on it as well as some interior shots.