u'r 5er should have a fresh water drain on the outside somehwhere ,, look for a small t shaped valve ,, that should be the fresh water drain ,, and as far as ur toilet ,, the leak could be the closet gasket ,, or leaking from the knife valve ,, does the bowl hold water ??? if it does then i would say the closet gasket is bad ,, if the bowl does not hold water ,, the knife valve seal maybe bad ,, if it is ,, then i would replace both the knife valve and the seal ,, stuff gets under the valve and tends to tear even a new gasket ,, hope this helps