I have a single-lever Moen kitchen faucet that's 12 yrs old and I'm trying to replace the original cartridge. Moen sent a replacement cartridge (1225 B), that includes a removal tool. I've removed everything that is supposed to come apart up to this point, including the retaining clip that holds the cartridge in. The instructions at this point look like this:
The cartridge is completely circular, nothing keyed. It has O rings top and bottom to seal it. The removal tool is a plastic cap that fits around some wings in the top of the cartridge. You are supposed to use it to twist the body of the old cartridge. The only obvious purpose for this would be to sheer any built-up scale that might be stuck in the various openings, or just to generally loosen the body.
Inside the body of the cartridge, there is a stem that moves up and down for shut-off/flow volume, and rotates for hot/cold mix. Pulling up on the stem is supposed to pull out the cartridge.
The cartridge is frozen inside the faucet. The removal tool just deforms. I managed to turn the cartridge body maybe a few degrees and now it is stuck there. I tried using a metal tool to turn it without success, stopping short of enough pressure to damage the plastic cartridge.
I've used vise grips on the stem in the up position, tapping them up with a hammer. I've used enough force to knock off the vice grips but the cartridge body doesn't budge. I've also tried a small pry bar as a lever between the vice grips and the body of the faucet. Nothing budged, and I'm concerned that the cast metal body is too brittle, and that using the thin top rim for leverage is likely to break it.
There have been some other questions here about removing cartridges. A common theme is using WD-40 or CLR. Aside from the poisoning potential of WD-40, the cartridge is a very snug fit and O rings seal the area where scale could build up. So it isn't obvious how I could get enough to where it could count.
Any suggestions for extracting the old cartridge?