You need a set of these to diagnose AC issues. First check static pressure and then the high and low systems with the engine running about 2K RPM's.

 

Ambient air temp also matters - it drives what pressure you should see.

There are charts you should use.

You might be low on freon, but don't just go pumping freon in without gauges. Too much pressure will cause your compressor to fail, or at a minimum, trip a switch and it won't run.

Like this:

or this:

 

Thanks boss

 

That's a $300 kit. lol Go get a bottle of AC pro with the gauge on it.

 

Ya know, if you plan on blowing your **** up

 

Those part store kits only give you half the gauge set picture. I had a guy pump 8 lbs of refrigerant (its not freon. Freon is r12, everyone after 93 is R134s) into his windrower/swather that only holds 4.5 lbs (I own an AC repair business). He ended up having issues beyond that. Most of those cans are 12 oz and a lot of cars (I havent looked at the s197 so Im not curtain) hold 1.5 lbs. If you dont have/buy/borrow/rent a gauge set, doing it yourself is extremely difficult, especially if you end up having issues beyond a low charge

 

It could also be because of lack of airflow. I know in cars I've sat in for hours at a time without moving, and I mean not moving, have had symptoms of bad A/C.

 

It's not a $300 set. I think I paid like $50 a few years ago. Yes you need them to diagnose your AC system properly. Just putting refrigerant in there is not always the answer. Putting refrigerant in there without knowing what issues you are having are will lead to bigger problems.

 

Dimora, thanks for the chart. I think I had a leak one of the lines is oily at the seam. I need to tighten it down and then get it survived.

 

Thats a good sign of a leak. Tightening it might not do it though. Might need a new o-ring/sealing washer but if you take it to a shop, it will give them a good start. Also, if you can, look at the compressor, around the pulley. That shaft seal is a pretty common place for a leak. It will be dirty just like what you described

 

Thanks I will give it a shot.

 

Let us know how it turns out

 

I developed a leak on the passenger side of the car. I replaced the prong and tightened the line down. I just need to get the system charged.

 

If it leaked out to the point where there was no longer freon, you should really have the drier replaced and have the system vacuumed out and filled professionally. It is well worth the $100-$150 to have it vacuumed and filled if that happened.

 

^+1 if its not completely empty you can get by without a new receiver/dryer but definitely get it vaced and filled professionally

 

That was my plan just need some time off to take it in.

 

Tightened the leak had the system vacuumed and charged and my ac works like a champ.

 

How much did it cost? I think I'm in the same boat as you.

 

Awesome

 

Im also curious how much. I doubt it took more than an hour (probably charged you an hr) and I doubt the s197 (I havent looked at the spec) takes more than 2 lbs of refrigerant.

 

Most shops vacuum it for 15 minutes which doesn't get 100% of the moisture out, especially if you opened the system to change a part. I'm vacuuming right now and will let it run 2 hours. A shop can't afford to do that, but I'll have ice cold air when done.

 

It came to 110

 

While we're on the topic, what would cause the A/C to be reasonably cold when I start it up, then over the course of 10 minutes it gets warmer and warmer until its almost like the heat is on?

My first thought is a blockage / ice or moisture in the system, but I don't know for sure. I only have a rudimentary idea of A/C....

 

If you turn it off for an hour, is it cold again when you turn it back on? If so I'd say there is moisture in the system that is freezing up and causing a blockage.