Besides , you need to pull the valve off anyway.

If you're really curious you can pull the compression nut & scussion off .

If it's a pin hole leak you should be able to hear it.....

I highly doubt it's a leak. Just change the angle stop to a 3/8 comp., and get a new 3/8 x 1/2 supply line.

Done

no galvinized there, it is a compression stop. eastman speedflex prolly, used to be really popular. not sure where you can find the threaded cone washers that would thread on the flex now but they prolly are available. if the copper is solidly supported in the wall you can usually take the stop off and work the comp nut and ring off, shine up the copper with good sand cloth, and have a new stop on in about 30 minutes. cutting wall is last resort because to do it right you patch the wall. exercise some patience and do both in about an hour, don't know what plumbers cost out there but not thinking it's a terribly expensive fix.

Are you talking about the corrugated copper vertical service line? I may have misunderstood. It looks soldered to shutoff fitting and needs sweated off. Or remove at stem or nipple and replace all as it looks threaded to stem.

I can post a pic of the best nut/ring puller in the world if you want.

Will have that nut off quick

http://www.amazon.com/Pasco-4661-Com...on+ring+puller


Once u unscrew the valve from the nut, that puller is the best thing since sliced bread to pull the nut &ring off the pipe without hassle

that's the way they were made, packaged, and sold. could get them in rough brass or chrome. wouldn't mess with it. the pics blurry but it is a compression fitting, prolly been seeping a little.

pawnmowwer has the right idea, just take it apart and pull the nut and sleeve and get a new stop on there.

Bad advice for a novice.

You're right. I looked at some coupons for a local plumber and his "specials" are generally 20-30 pct higher than my everyday prices.

Wow. the number of comments telling you to open the wall -- NO. Don't.

If the valve is working fine (not leaking, shuts off when you close it) you should be able to attach it to the new faucet at the faucet. i.e. up at the top of that flexible hose you should be able to thread/screw the old fitting into the bottom of the new faucet.

Now, the new faucet pipe might be a different size from the old one. You can buy adapters.

Otherwise, you all need to remove the shutoff valve from the wall and put in a new one that matches your line from the new faucet. Looks like you have 1/2" copper pipe coming out of the wall and this is a compression fitting / valve. More pics of each piece would help.

Can you get a couple of better pictures. High Def please. This could be a simple fix.

You'll need to Un sweat the valve to get it off. Get a new compression stop and a new lav supply. If you don't understand any of this, call a plumber who will fix it in a few minutes. It'll cost you, but it's better than flooding your house

no need to break out a torch unless you go nuts and break it off behind the wall. new stops should not set you back more than $11 apiece, prolly less than that, 3/8x1/2 sst flexes $7-10 or so. you should be able to pull off nut and ring with little trouble. usually they only won't come off is if it is rolled copper which is highly unlikely in this case.

if you have any doubt call a plumber, surely there is a reputable company in your area that doesn't flat rate you to death. my guess would be it would be no more than a 2 hr job if you had them throw on the faucet while they were there.

If you call a plumber over there is only 2 possible outcomes

Porn or murder

A unseen 3rd outcome might happen and you might get your plumbing fixed and he leaves