A/C question for the mechanics here...Please help

for a car that age, your local auto parts store will have replacements most likely, and certainly cheaper than buying same from the dealer
if you have or are taking apart, be sure to cover the open ends, and prevent moisture/humidity & dust in the system until closed up again
ask when you purchase the replacement lines, for them to look up the amount & spec of replacement charge
another option, once replaced lines yourself (be 'extremely' careful of O-rings during & do not reuse old O-rings anywhere), is to have recharged by a local shop, they will have a machine which will purge & refill the system
good luck!

 

It's pretty reasonable to expect the new parts to come with o-rings.
You'll know for sure when you pick it up at the parts store! You can probably look at pictures of the part you'd be ordering online if you're going that way. I like RockAuto.com for my online window shopping needs.

The old rule of thumb (growing up in Texas, we get a lot of those about repairing air conditioning) is that if the refrigerant didn't blow out catastrophically, you don't need to add any oil. So you'll only expect to lose the oil in the dryer. Maybe a couple of ounces, rule of thumb.

 

no need to take to shop for refill until after you've replaced hose(s), it's going to evacuate (what ever is left by now) once you open it
if you haven't disconnected hose(s) yet, wait and have replacements in hand, then do all at once, to limit contamination to system
don't run the system in between time, nor until you've had shop do refill

 

i'm not sure, they use to sell the whole kits for recharging yourself, but those have been pulled from many store shelves now ...it might be worth saving the headache to have a shop do, many will have spring sales for lesser $

 

Doing the work yourself isn't an issue. The only part that's difficult is reclaiming and then charging if you don't have the equipment. I wouldn't recommend recharging it with the little cans from the store, it's hard to judge how much and over filling the system can create as many issues as under filling. More so on newer cars but most shops shouldn't have an issue pulling a vacuum and then charging for you.
As for the hose leaking, it's common. And the hose and drier shouldn't be hard to change, just make sure to lube the orings really well. And you shouldn't need to add much oil, just a few ounces at most.

 

It's not as exact as you might think. Autozone has the cheap gauge that comes with the freon. Without the gauge this is what your looking for: the line set to start sweating (or condensation if you prefer. If the line is freezing or icing the freon is still low). Some receiver dryers have a glass bubble, you can watch that to see if there is the correct amount. The ac clutch on the compressor will not start to engage until you barely have enough freon. Watch that as well. The engine will be running and the ac on to take the charge.

 

If you're going to do it by pressure, then you should be able to find the pressure that corresponds with your ambient temp on the net. Just charge it to that point.
Try it for sure, you can always have it done later at a shop if needed. Just don't put any AC stop leak in it...