Moen extensa kitchen faucet rusted out?

wildlegend · Feb 12, 2015

I have a Moen extensa 7560SL that I inherited from the prior homeowner (warranty not transferable). It was originally installed in March of 2006, so it's pushing 9 years old. I have enlisted a plumber for one or two cartridge replacements (to solve dripping), and most recently replaced it myself this past August 2014.

Over the past month or two we have noticed the faucet will resist being turned side-to-side (sink-to-sink), with a rough scraping feel. This is mainly noticeable as the faucet head swings by the center position (in between both sinks in our double sink).

I contacted Moen, who told me that the model can sometimes "rust out" the turn valve, and require full replacement. I found a couple instances of this symptom happening to other folks on various message boards.

I purchased a new Extensa from the local plumbing supply store, and studied it visually for a bit. My questions are:
1) What part is rusted out? It's hard to tell by looking, even at the new exposed model.
2) Does this sound like a correct diagnosis by Moen?
3) Does replacement sound like the correct solution?
4) What could have caused this? Was it my attempt to change the cartridge myself? Some water did spill about as I pulled the old cartridge.
5) Anything I should watch out for as I attempt to change the faucet out? I see some corrosion underneath where the faucet is fastened to the sink cutout.

Attaching some pics. Any thoughts are appreciated.

Matt30 · Feb 12, 2015

Under where you are pointing your finger is a stack of o-ring seals. When they dry up or become dislodged, it will become very hard to turn. Usually an o-ring replacement and some plumbers grease will do the trick and get things working smoothly, but it's not unheard of for it to be beyond repair.

Depending on what's in your water, it can rust, Pitt, or scratch the brass on the faucet, once damage its done, it's time for a replacement.

wildlegend · Feb 12, 2015

Thanks Matt30. So I'm guessing that in order to properly diagnose this, I need to disassemble the existing faucet - loosening the corroded nut from the apparatus underneath and threaded center spindle, and pulling the whole faucet up - to see whether it's an o-ring problem, or worse.

Do I have that right? I don't mind, I just want to verify.

Interestingly, the faucet seems to "loosen" if you give it a few pushes back and forth, and it only "seizes up" after long periods of inactivity.

Matt30 · Feb 13, 2015

You can take the faucet apart from up top. Only go after the bottom but if you wish to remove it from the counter top.

Under the Moen logo on the handle will be a set screw you need an Allan wrench for. One the screw is all the way out, you can take the handle off and unthread the dome. You may have to remove the cartridge to proceed further, be sure to turn off the water. to remove the housing you will have to get the sprayer hose out of there.

You should be able to find a manual online, or Moen will mail you some with a new pack of o-rings. They are specific to the faucet, universal o-rings will not work.

wildlegend · Mar 8, 2015

Finally got around to fixing this today. I disassembled the old faucet to find it was completely rusted out on the inside. The supply lines, cartridge, and mixing tee/area looked fine, but there was a metal "sheath" wrapped around it that was all rusted out.

I replaced it with a new Extensa from my local plumbing supply and it went without a hitch.

The hardest parts were (1) physically squeezing under the sink, and getting my hands in tight spaces to remove the old faucet and (2) figuring out why the supply lines kept dripping even though I had the local shutoffs and main turned off. In the latter case, we guessed that the upstairs lines were somehow bleeding back into it, so we opened all those faucets, and eventually it slowed to a every-few-minute-drip, allowing us to make the switch.

Thanks, Matt30