Our 2001 Sable's A/C is only blowing cool, and max AC is needed to get the temp appreciatibly down. It's been degrading slowly, and nothing has been done to the AC since we got it 2003, so it is time to fix it.
Is it normal to slowly lose refrigerant over such a long time? If so, is the lubricant also lost? If the oil is still in there, recharging it myself doesn't seem like a difficult job.
If oil is lost, or there is leak, about how much should I expect to pay for shop to leak test and recharge system?
Over time the O rings in the system degrade. If its just a slight leak, you can get a can of Freon, oil, and stop leak all in one, with a hose attached to it for under $20. If its a bad leak I'd take the fittings apart, put new O rings in, then pull it down to a vacuum, and refill. Right now I'd try the $20 option and see what that gets you.
Have you done the $20 option yourself? I considered it, but the consensus at a Taurus/Sable site was that those cans can cause more problems by inexact measurement of added refrigerant and adding extra oil.It could just be arrogance of doing something the easy way instead of the 'right way', but I have no experience on the subject.
In my limited experience, having topped off from cans like that 4 or 5 times on 3 vehicles, the inexact measurement is a non-issue. After topping off with cans and a cheap 1-gauge hose until the gauge is somewhere vaguely near its green zone, I will have properly cold A/C until it all leaks out again. Perfect ratio of oil to refrigerant seems unnecessary, as does perfect amount of contents of the system.
Super Seal is highly recommended as a stop-leak but did not stop my leaks.
$45 at Walmart or $35 after coupon code at Advance using online order with in-store pickup. Actually, I can't find a currnet $20 off $50 code, so $45 at Advance using code RETMENOT124.
Anyway for that money you get a kit with plenty of cans of refrigerant, stop-leak, and oil, a hose/gauge that works well, and some conversion fittings that you'll discard.
turn on A/C
make sure compressor is running (short or open the pressure switch connector if necessary)
hook up can and start filling, following its instructions about holding/shaking it
When each can is near empty, heat it carefully and gently (thanks to Jay for that tip!) in a bucket of warm water to reduce waste. As the can empties, the effect is the same as how it operates in your car; the can gets cold and its contents condense, reducing volume and therefore pressure. Adding heat to the can until it's room temp (or a little more) expands the refrigerant. Otherwise, when it stops moving refrigerant into the car and you disconnect the can from the hose it will spew a ton of refrigerant, wasting your money and gratuitously polluting the air.
Thanks for the advice. I used all three cans in that kit, and it didn't seem to completely fill the system, but it is colder. I did hear a hiss when I shut the car off for about 5 secs. I'll recheck the pressure in a few months, but it should be good for another couple years at least.
I'll just throw in that I recently changed the cabin air filter after about 60k miles. The old one was completely clogged. After putting in the new filter, it was a night and day difference. The air was colder and the airflow was greater.