Hi, MCPO! Thank you for your question. The RP25513 stem unit assembly works with the RP4993 seat and spring kit. Here is the link to this kit: https://www.deltafaucet.com/parts-product-detail?modelNumber=RP4993 Best Regards, Rosanna

Hello Mike, Thank you for your inquiry! Below is a step by step walk thru on how to install each stem unit and 1/4 turn stop. 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. Best regards, Tanya

Hi, John Very! Thank you for your question. The RP25513 works in both the hot and cold valve ends. Please verify that the hot and cold supplies are turned off before disassembling the faucet. For both the hot and cold valve, install the stem with the permanent white stop on the right side. The removable 1/4 turn stop should be installed in the back on the cold side and in the front on the hot side. Next, tighten down the bonnet nut and rotate the brass stem so that the flat side is facing away from the spout (off position) and attach the handle. Best Regards, Rosanna

Dear Wknowllen, Thank you for your inquiry! The Delta Stem Assemblies RP25513 and RP25513-3 are the exact same parts. The RP25513-3 comes as a pack of three stem assemblies. Best regards, Tanya

Thank you for your inquiry, Manny! The RP78201 stem units are actually the RP25513 stem unit assemblies. They will work in your Delta Lewiston Kitchen 21902LF faucet. Best regards, Tanya

Dear Mike, The Delta Stem Assembly RP25513 can be used with a H678RB handle, you would just not use the 1/4 turn stop piece that comes with it. The RP24096 is the stem assembly that does not come with the 1/4 turn stop. Best regards, Tanya

Dear Independence, Thank you for your question! The oring that is on the Delta Stem Assembly RP25513 is not a replaceable separate part. To replace the oring you would simply replace the full stem assembly. Best regards, Tanya

They cannot. Delta sent me RP47422 for my faucet model 35902-SS and after installing it, the faucet would no longer turn off. I figured out that I need RP25513 even though their spec sheet lists RP47422. The bottom of the stem assembly is completely different.