Hi. I have an old kitchen faucet. I replaced the valve stem to the hot water side because it continually dripped. I had to get this part at the specialty store because it is so old. Anyway, I replaced that faucet was fine. Just the other day the hot water ended up having no pressure. I used it then went back to use it again and it was like that. I have no idea what is wrong. The cold water is fine. Any ideas how I can fix this?