Sorry. Only the last couple of sentences came thru
The problem is where the hot water line makes a 90 degree turn under the bathroom Sink going up to the faucet.
It will start leaking around the rubber washer that should seal the fitting.
The hot water line at the kitchen sink gives no trouble, neither does either one of the cold water fittings.
I have replaced the rubber washer, replaced the complete fitting including the 90 degree elbow, put new pipe from closet to the fitting.
Maybe all this will post.
Thanks for letting me know that the whole statement didn't make it.