Yesterday while taking a shower the water pressure fell to a trickle for about four seconds then came back again. This went on for the length of my shower. Today, while washing a few dishes the same thing happened but for a few seconds longer. I went down to check the pressure and noticed that I only had 20PSI. I taped the Pumptrol D a few times and let out some water from the valve and it went up to forty but it was higher before. I noticed that the adjustable control (the smaller one has some oxidation on it). Do I have to change the Pumptrol D or can it be something else? New Homeowner! Thanks..