Having a problem removing the single lever kitchen sink faucet (moen, model number M 7800). There appears to be no rust or corrosion everything looks new on the underside of the sink. I've tried various wrenches , but nothing will budge the large nut that secures the the faucet to the sink. I'd rather not try to remove the sink and disposal. I've tried getting some information at the manufacturer's web site, but apparently this particular faucet and information about it is no longer available. Would appreciate any suggestions.

Thank you

 

A large jawed basin wrench would be the best bet for this. The jaws would lock onto the nut and the long handle would give you more leverage.
Hate to ask a stupid question but, are you turning it in the right direction? Many people forget that they are turning from "under" the sink and turn it the opposite way. Just a thought. Good luck.

 

Sometimes that faucet can be little difficult to remove. Here are a couple of techniques I've used:
1.) Cut or break the copper water supply tubes off to give you more work room. Get a large deep well socket and extension. Someone may need to hold the top portion of the faucet to prevent it from turning.
Or,
2.) Get out the Dremel rotary tool and put on the fiberglass cutting disc. Cut a diagonal slot right through that nut. If memory serves, the nut is brass and cuts like butter. Shove a screwdriver in that slot and turn. This will open up the nut or even break it in two.

Good luck and let us know how it goes.