Maybe I missed something, but is the leak around the bulkhead fitting hole, or on the threads of the bulkhead fitting? If all else fails, a fool proof way of sealing that sucker, is to trash the rubber gasket apply a bead of silicone around the bulkhead fitting. Install the fitting, and let cure. Then put PVC glue on the fitting threads, and install your hose connector. Let cure. It'll trash the fittings if you ever want to remove them, but fittings are cheap, and it won't leak. 