I had very low water pressure coming out of my bathtub spout and the shower diverter was faulty so I removed the spout. The pressure was low coming out of the 1/2 inch copper pipe.
I then replaced the Moen 1222 single handle cartridge. It was extremely stuck and when I finally got it out the black silicone "plugs" on either side were stuck inside the supply lines on each side. I removed the silicone, used CLR and flushed the line. Water shot out like a fire hydrant!
I installed a new cartridge and again had almost no water pressure. I purchased another cartridge in case it was faulty, tried blowing out the pipe installed the new cartridge and was back to the initial low pressure out of the tub spout that I started with. After soaking and cleaning my tub spout I reinstalled it and could not get water to go up to the shower.
I have a new spout to install but am hesitant because my water pressure is still so low. Since it shoots out without the cartridge I feel something must be stuck between the valve and the drop pipe to the tub. As far as I can tell the valve does not look to have any corrosion. There is just one very small hole in it that could lead to the tub spout and I'm wondering if it is too small of a hike or if something is just stuck in there?