Same faucet, same exact problem. Delta sent me a new bonnet and cartridge, told me to cut out the stuck bonnet, being "careful not to damage the other parts of the faucet." Good luck with that! You would have to somehow get the cartridge, which is held in by the (stuck) bonnet out of the way, then saw through the side of the 3-inch long bonnet sleeve, without damaging the female threads at the base of the faucet. I doubt anyone has ever successfully performed that surgery.
So I tried the 15-inch crescent wrench. No dice--the whole faucet turned, including the cartridge, and further torque would have busted the whole faucet. I WD-40'd, liquid wrenched, and vinegar-watered the heck out of it for a week. I tapped it with a hammer, and threatened it with a propane torch, but it just would not budge. At this point, the sensible course of action would have been to trash the crummy faucet and replace it with a new one. But it had become a battle of wills, and I was determined to get that s.o.b. off of there, whatever it took. So I got myself a 1-5/16 inch deep impact socket--money being no object at this stage--6 point, 1/2-inch drive, to fit the top of the bonnet, connected to the air-impact wrench with 130 psi in the compressor tank, liquid-wrenched it a final time, and then blasted away--first CW, then CCW--repeating for half an hour on and off, until the s.o.b. finally broke loose. That thing was on there tighter than any car or truck axle nut I have ever encountered!
The faucet looks and works good, and I appreciate Delta standing behind their warranty with the free replacement parts. But I can't help wondering: what is the point of a replaceable faucet cartridge if you can't remove it due to a stuck bonnet nut? It's a deal breaker. Can anyone recommend to me a different faucet that doesn't require busting loose a frozen bonnet nut to access the replaceable part?
View attachment 72891
