'97 Corolla A/C has Leak
 

Our 2nd car is a 1997 Corolla, which for a long, long time has not had A/C. For a period of time it was in my sister's care and last fall it came back to us. What I know is that the A/C can work, but it has a leak. I was told that last summer an A/C recharge kit from an auto store was put into the system, but it only worked for one day. So I think this seems like a decent indication that the system can work, but the leak needs to be found.

I went to one of my local auto stores, asking about an A/C recharge kit. My idea was to use the recharge, make sure that the A/C is working, then if it all leaks out overnight, find where it's leaking. The suggestion by the employee was to take it to a shop and have them do a dye test and fix the leak. I was hoping to avoid a mechanic in order to save both time and money, it's not an ideal time for me to have to pay a mechanic's bill - I'd actually rather save the money and continue driving with the windows down. For some reason I thought it would be cheaper to diagnose the leak myself then decide if it's something I wanted to fix right away depending on what the problem is. I have read that it's common for the evaporator to develop a leak, but I don't know much about the A/C system.

Any suggestions are appreciated.

If you don't have a vacuum pump, you can't really do a proper repair, and will have more trouble later on, especially if the system has been depressurized for a long time. Unfortunate A/C repair is best done by those with the proper equipment/knowledge.

You almost certainly won't be able to find the leak yourself (it's obviously a pretty slow leak if it takes a day to leak down, and the refrigerant is a gas at room temperature/pressure, so it won't leave a puddle or anything), and even if you did, you almost certainly don't have the necessary equipment to repair it and purge the system and refill it properly. Your parts store people gave you very good advice IMHO—advice that, I might add, cost them the sale of a recharge kit in the short term. That's a good parts store to patronize.

As you aliude to, here's no reason you need to fix the AC; it's not like a problem with the AC will spread to the rest of the car and you'll suddenly find you have a leak in the gas tank or something. (If you're driving on the highway a lot with the windows open you may wish to get a pair of earplugs to avoid damaging your hearing; the noise can be deceptively loud.)

Thanks, Spreadhead. That makes sense. I didn't know if those were kinds of tools that places like AutoZone rented out. But it does sound easier having someone else do it.