Moen Shower Valve - Cartridge Removal Issue. Plastic Mounting Adapter in the way

[TheRealDanno]

Amateur DIYer and first time poster here. Hi everyone! I was going to replace the cartridge on this Moen shower valve (Legend model) but after I removed the handle I discovered this unusual black plastic housing (mounting adapter) which I want to remove so I can get the cartridge out but I was hesitant because I did not want to break it and then be in bigger trouble. There are no screws on the outside of the chrome hubcap (escutcheon) housing that I can see. But I think (maybe) this black plastic mounting adapter might be screwed onto the valve behind the chrome escutcheon which would mean removing the nice caulking job taking the “hubcap” off and getting inside to unscrew it (hope I don’t need to). This assembly is about 20 years old. Obviously, I want to remove the old cartridge so I can replace it. I have the replacement cartridge (Moen 1225) I just need to know how to proceed to get the old one out without damaging anything. It’s just the darn black plastic extension is in the way. Any help would be greatly appreciated.

 

[TheRealDanno]

PS - I should have mentioned the model number of the shower assembly. It’s Moen model L3189 (style C) which is the one that has the black plastic mounting adapter unlike styles A or B which have the usual setup of just the brass stop tube. I found a picture of the mounting adapter. Cheers!

 

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[Oldyellr]

I don't know why the escutcheon would have been caulked unless your shower enclosure is very irregular tile, they have a rubber gasket surface. All parts have a lifetime warranty and you can pick them u at your nearest Moen dealer, or contact them by email,takes a couple of weeks.

 

[TheRealDanno]

Well there was no rubber gasket and I decided to remove the old caulk and attempt the repair. The plastic extension piece was in good shape. Thank god because they are impossible to find. Maybe Moen has them but they're a pretty old part (circa year 2000) so maybe not. Anyhow I just turned the screws to the off position on the shutoff valves and disassembled all the little parts keeping in mind what order they went in. The cartridge was a little fiddly to fit in so the retaining pin would slide in properly. I think I had the cartridge positioned wrong at first. The good thing is it all snapped together like a puzzle and the shower does not drip anymore. Moen came through with a free replacement cartridge making this a repair that cost me $0.00 and gave me the satisfaction of fixing something all by myself. This site was a big help so thank you Mr. Love.