PaulW

Thanks, but I would rather evacuate the system and then recharge the right amount. I think it's the best way to go.

pw

A8CT

and gauge attached - about $20. Will these work on the A8 ? I thought someone a while back said the charge port wasn't accessible. If it is, give shot. Its worked 6 mos for me and I was basically blowing lukewarm air.

GDJT Allroad^2

only seem to have the higher-pressure side open.

PaulW

Correct, and it needs to be charged with the system off

im_cecil

Gotcha. If it's that slow, your ideas make sense. Leaks can expand, though...

gondar

One of the smartest things I ever did was buy a small Robinaire vacuum pump. This was 20 years ago. I had to buy a new one but there are now all sorts of cheap-ish pumps on ebay. You need a quart of pump oil, too.

I have used it many times, and have loaned it many more times times. You get a much better job letting the pump run overnight which you can do if you have one. I just had a new five ton R22 system installed in my home and I put my pump on it all night so I know the system is dead-dry. The technician thought this was excellent practice.

After you pump a car down you can charge slowly into either high or low sides, with the engine off, using temperature differential and a scale. Just make sure you don't liquid lock the compressor becasue it is a vapor pump, not a liquid pump.

I have one car that seems to have only a low pressure port for R134a, I have added little twice but never had to pump it down.