Thank you for your inquiry! Here are the step by step walk thru on how to install each stem unit and 1/4 turn stops, so the handle turn correctly. I hope the information is helpful.
Hot side ~ The stem unit will go into the valve with the raised white portion of the stem toward the spout. When you install the stem into the valve, you should notice 2 notches in the brass valve body. The stem unit will have a piece in each side that will fit into the notches. These notches should be facing the 3 and 9 o'clock position, if you imagine a clock face. With the stem installed in the valve, you will need to insert the 1/4 turn stop into the slot in the front of the stem unit. Now you will want to tighten down the bonnet nut that screws onto the valve body. Once the nut is hand tight, you might need to reposition the brass arm that is straight up and down on the stem unit. The flat part of this arm should be facing away from the spout. So it should be in the 9 o'clock position. You can rotate this arm by grabbing a hold of it and just twisting it. Once you have it in the 9 o'clock position, you should be able to reinstall the handle and tighten the setscrew. Now when you turn the handle, it should turn toward you.
Cold side ~ The stem unit will go into the valve with the raised white part away from the spout. So if you image a clock, the white piece of the stem will be facing the 3 o'clock position. Again, the stem should fit into the two notches at the 3 and 9 o'clock position. The 1/4 turn stop will actually be installed the the back side of the stem. Once that is installed, you can tighten the bonnet nut over the valve and screw it down just hand tight. Grab a hold of the brass arm and twist it until the flat part is facing away from the spout. Again, it will be in the 3 o'clock position just like the white part of the stem. Once that is facing the correct direction, you should be able to install the handle and turn it toward you.
Date published: 2018-02-27