I tried to change the cartridge in my shower. Home Depot plumbing "expert" said the Moen SKU 1200 was the replacement, and it looked very similar to the naked eye. However, when I tried to install it in my shower it would not go it. I added silicone and it still did not work. After unsuccessful attempts I reinstalled my old cartridge and it stopped the leak, however I have a very small drip, which tells me I need to have it changed. When I put the original cartridge back in it too was difficult to reinsert. Is the SKU 1200 Moen Cartridge the same as the SKU 1201 Moen Cartridge?? If not, what is the correct replacement SKU?

If it looks the same, it is the same. Not that many types.

When installing cartridge, put the cartridge in with the stem in the open position. If this is the old style, pull out and turn type, that would be with the stem pulled out. Otherwise, as you try to push the cartridge in, you are having to compress the air trapped in the body of the faucet.

When you put the old cartridge back in, the defect that causes the drip allow the air to escape.

Hint: Had you called 1 800 BUY MOEN, Moen would have sent you a new cratridge for free.

Not sure if the same type, but when the old one is out, I use the inside pipe brush, then the silicone. Not sure if this is Plumber accepted, it works for me.

Strat,

Hopefully you mean a silicone grease, don't think I would use a wire brush, might put scratches in the polished brass surface inside the valve.

Post some pics please