I'm trying to replace the valve stem of a 2-handle bathroom sink faucet. All the instructions I've found online say to unscrew the nut atop the valve stem.
But my nut, when it turns, also turns the entire assembly. I assume the stem has gotten stuck to its housing.
UPDATE: I ended up removing the entire valve assembly. Then I wire-brushed off lots of gunk to get a closer look at the parts. But I still can't remove the valve stem from the rest of the assembly. I'm starting to wonder whether it's supposed to be removable.
I don’t know the model number because the faucets were installed long before we moved into the house, but the markings on the outside of the valve assembly say this: "GROHE A 98 01 R 90". A Google search yielded nothing useful about replacement parts or service info, nor did Grohe's website.
Question for anyone with experience with Grohe faucets-- are the valve stems removable? Know any tricks for unsticking a stuck stem?
I attached a new picture.
Here's the old picture from before I removed the valve assembly from the sink: