plumbing

I plumbed my trailer from the tank to all the faucets. I used PEX pipe, brass full flow valves before the supply lines, braided stainless supply lines to everything. I rebuilt the 44 year old faucets with new washers. I've found that plumbing is one spot where saving money is not efficient. If I have a leak and have to come back to it later, any money saved is blown away.

Replace the fitting that you just tightened. Probably just get a new faucet while you have the fittings loose. Nothing very special just get what you need at Lowe's etc.

Don't connect them direct I had problems with mine till I replaced the direct connections with the braided faucet hoses.

Usually faucets in RV's are made by pheonix. First time they leak replace them with one from a hard ware store. I usually replace them with moen. Look the same but last forever.

I replaced all my faucets in my older Fleetwood and never had a problem, the Winnebago leaked from day one and the dealer claimed to have tightened them also.

How tight are you making them? Seems to me there is a reason? Either your not getting them tight enough or something???