The water pressure in our added bathroom has been decreasing. The water trickles out of the pipe even with the shower head off. The presseure gets a little better after the water has been on awhile. The pressure in the run before and after is fine. Last spring my well pump failed, and I replaced it. Could sediments have accumulated in the elbow that leads up to the shower head and this is why some pressure is restored after the water is running for awhile? If this is so, how can I rectify this? Or any other suggestions.