I am trouble-shooting a tub and shower that has gone to low flow, and I suspect I need to get at the mixer cartridge.

I've got the faucet removed (white plastic pipe in pictures) and have gotten down to the faceplate, which is two pieces: the circular one in the center, and the larger oval-shaped back. I've worked the back plate loose (adhesive seal and caulk holding it to the wall), but the center, circular face plate, which is not attached to the larger, oval-shaped plate, has me stumped. I have no idea how it comes off.

Does anyone know what I'm missing here as far as taking this apart without just breaking the plastic faces and attempting to replace them (which I really don't want to do)?

Any help would be greatly appreciated.

Mike

I see a trim-ring in the middle of your faucet that screws over the plastic stem in the middle of the plate, attaching the smaller faceplate in process. It is usually hand tight. If not, than take pliers and gently turn it counter clock wise.

I'm guessing that I'm going to need some channel-locks for that? Regular pliers don't have the span of grip, and that sucker seems to be good and tight.

Sure, Channel Lock will give you better grip. Make sure you turn off your h/c water supplies. That cartridge is under pressure. Let us know how you did...

No dice

The chrome-colored plastic collar (trim ring?) came off with the help of the channel locks but the faceplate still remains. I also don't know how to get any further into the faucet assembly, as the brass collar I found underneath the plastic one is quite secure, even with the water off and pressure relieved.

Call Delta Help Line. They will lead you through the process of removing the trim.

Some trim plates snap in. Also, some trim plates attach to one each other with velcro-like tape. See if you can insert small flat screw driver behind the small plate. See how much resistance it has. Also see if there is one strong point of resistance. That's where the point of attachment is.

I got it. It turns out I was squeezing the brass nut too hard.

Now that I've got the cartridge out, is there a way I can tell if it's bad or not?

Bingo ! Congratulations... now you are Delta Trim Removal Expert ! :D

Now it depends how old the cartridge is. If it is an old cartridge, replace it. We always do. They are not too expensive. Home Depot / Lowe's sells them. You will be set for next few years. Don't try to replace washers or "O" rings (if it has any).