Moen and Groan

Yesterday I had the pleasure of having to replace the valve stem from our master bath shower. My wife reported that it was leaking through the handle, which of course is attached to the valve stem.

My shower faucet is originally a Moen. I took the handle off, as well as the decorative round plate that covers the tile and hides all the ugly inner workings.

I'm used to dealing with plumbing components that are screwed into some kind of receptical. This one looked like it was somehow seated inside a small, short pipe extending from the wall. I couldn't see any way to unbolt or unscrew the valve. I also noticed a small tab on top of the end of the pipe and I was able to pull it out with a pair of pliers. It was a retaining clip, leading me to believe that this was all that was holding the valve in place.

After turning off the water main to our house, I took my pliers and pulled on the end of the valve stem but it just wouldn't come free. So, I decided to go to Ace hardware for some help. I turned the water main on (without replacing the retention clip) so my family could still use water and left for Crown Hardware.

Usually the Ace hardware store in our town of Lake Forest, Ca (the one in Orange County that used to go by the name of El Toro) has plenty of good help, but yesterday they were all busy. I just looked at all the valve stems they had and found one that looked like the one that was in my shower. It would later prove to be the correct one, called "Brass Faucet Cartridge" item number 43486 (replaces Moen MO-1).

I got home and turned the water main off. The directions that came with the faucet cartridge just said to do what I had already done: remove the retention clip and pull out the old cartridge. So I decided to go on the internet and do some Google searches.

I found this on one of my searches:

This was conspicuously missing from the instructions that came with my faucet cartridge. It shows using a pair of pliers to twist the valve stem cartridge with a square white cap.

That explained what the square white cap that came with my valve cartridge was for.

So I placed the white cap on the end of my valve stem and twisted it a few times, causing the whole cartridge to twist around inside the pipe it was seated in, then tried to pull out the cartridge.

It was still stuck. So I went back and did a few more internet searches, and found out that a tool is available to pull out Moen faucet cartridges. They wanted about $24 bucks. More internet searches on Home Depot and Lowes gave me the sinking feeling that I wasn't going to get this tool, and besides, I was kind of ticked that I was going to have to part with $24 on a tool I was probably going to use one time.

So being an engineer trained in physics (common sense frequently escapes us) I decided to go back to the plastic white cap and twist it around 50 times and hopefully loosen the cartridge. I was quite surprised when my plan worked; this time the faucet cartridge came out without too much difficulty.

The new cartridge slipped in very easily. I place the retainer clip back in and turned the water main back on.

This is where things get entertaining. I didn't get the retainer clip seated correctly so the retainer clip tab was sticking up too high, keeping me from replacing the chrome sleeve that covers the unattractive pipe containing the faucet cartridge. So, Mr. Brilliant Engineer decides that what must be done is to remove and reseat the retainer clip without giving any thought to the fact that the water was on, with full pressure pushing on the cartridge from inside the pipe.

After removing the clip, the water pressure almost immediately pushed the cartridge about half way out. The pressure was so great I couldn't push the cartridge back into the pipe. The main water valve was located in the front of the house, and I was in the back. Could I run for it?

I yelled for help and neither my wife nor my daughter heard me.

Just then the cartridge shot out from the pipe into the shower stall. Fortunately, it didn't break any tiles. While five gallons a second (it seemed) shot into the shower, I sprinted for the front of the house and turned off the water main.

I came back into the master bath and naturally water was everywhere. I had neglected to close the shower door.

I was able to push the cartridge in securely enough this time to correctly seat the retainer clip and finished the installation.

The most ironic thing about this training session is that by the time I need to replace another Moen cartridge I will have forgotten everything I've learned.