I live in a 1995 Masterpiece doublewide. For years the hot water pressure has been horrible in the second bathroom. Here of late when I turn on the hot water, there is a knock or bang and then the hot water cuts off automatically. Also there has been some black rubber substance coming out.

I live in a 1995 Masterpiece doublewide. For years the hot water pressure has been horrible in the second bathroom. Here of late when I turn on the hot water, there is a knock or bang and then the hot water cuts off automatically. Also there has been some black rubber substance coming out.
Sounds like you had a faucet washer disintegrate and now the pieces are blocking the flow. Shut the water off to the faucet and open it up. Pick out the black pieces of nthe washer and then turn the water on for a moment to flush out the faucet. Purchase a new washer and you're back in business.
Toi tell you more I'll need the brand namd, Type of valve and all the details you can give me. Good luck, Tom

Good response , Tom !