Don't know if anybody else has this problem, however I've been fighting my home air conditioner for several years. It leaks Freon and shouldn't. Trane outdoor units.

For the first few years, I would call the AC guy out and pay him $200 to recharge it. Then I was talking to my Brother in Law, who has an AC license and he came out and did it the next time. System works fine when charged, but leaks the freon out.

Well, I got tired of that, so I got my own AC license, so I could buy the stuff and bought a can of Freon and some gauges. I even bought a leak detector, but couldn't find any leaks around the coils or the compressor.

Well, I finally figured out the source of the leak. It was the stupid Schrader valves and caps. Trane uses solid brass Caps, without O-rings. I stuck some o-rings in the caps and cranked them back down - no leaks. I spent maybe a thousand dollars on a 50 cent problem. I wonder how many other people fight their AC system like this. The repair guy kept telling me I needed a new system - when it ends up the one I've got works perfectly. I wonder how many people fall for that sales line.

I find the AC license is really a license to prey on ignorant consumers (until now me). Don't try to find decent information online either - you'll find nasty contractors telling you you'll ruin the environment - except in my case they were letting the stuff leak until I fixed it.

Anyway, I was clueless about AC prior to this, and I had to learn it, so all was not lost. Rant off.

Wow, great tip. Glad you solved the problem. I've heard valves can be problems in tires, in fact my brother just had a leaky one, but would have never thought about it for an A/C system.

How much did the AC license cost you?

I usually don't have any problems once I tell them what I do for a living.

Dateline or 20/20 had a story like that on bad AC companies charging for bogus repairs.

I stick with Industrial stuff. Indy, you have a reason to be upset it looks like. You could call the AC company up and let them know you fixed THEIR problem.

Seems standard operating procedure for alot of companies to just sell you new units as they lack the skill or desire to repair you current one.

Another case of consumers having to become experts in every conceivable area just to stay alive.

What's involved in getting the license? I've thought for years about becoming AC knowledgeable but never thought about the licensing aspect.

Partially true.

More profit in replacing than repairing. Sometimes it does make more sense to replace. Indyboater's case, however, isn't one of those times.

The so-called experts always preach more profit, more profit. That's ok, but some companies push it too far.

Again, we're not all slime ball crooks. Move on until you find someone honest. They're out there, you just have to find them.

I usually find them, get what is needed and then they go out of business. For example; my central air unit. Looked at a few different ones with a few different companies a couple years back, settled on one I felt was very good and a reputable company in the area. 6 months later they went out of business.

Please let me know your company name if you are in the Detroit area. I promise I won't call any of my BABC friends.

Indyboater

Could you provide a pic of the valve and where it is located? My AC Trane system just quits working over the weekend when we were out of town. The last time the AC guy came out he said I have a slow leak (few months ago) and he recharged it. Now my AC is not putting out cold air, although air is blowing out of the vents. My AC is central system: one part outside and part in the attic.

Thanks

Same as mine. Schrader valves look just like automotive valves on your car tires - just bigger. And they have brass caps on them instead of plastic ones.

They are located on the outdoor unit, on the refrigerant lines that come into and exit the unit.

Assuming your blower is working, It's hot outside, and the outdoor unit is working - the fan is blowing and the compressor is pumping, then it's easy to tell if the system is working. The big refrigerant line should be cold, and the smaller one should be hot to touch. If they're not, then you aren't refrigerating correctly.

You buy a set of AC gauges and hook them up to the schrader valves - the blue hose hooks up to the cold (Low Pressure)line and the red hose hooks up to the hot line (high pressure) - pretty easy. Then you can tell exactly what is going on with the system. It's not rocket science.

Then you buy a can of the correct refrigerant, and you hook the third line(yellow) up to it and recharge the system into the low pressure (cold) side. But you do have to have the gauges and some knowledge in order to do it.

One thing to do, if you have a trane system is take one of the caps off and see if it has an o-ring in it. Also they should be more than finger tight - you need to use a wrench to get them on or off. If it doesn't have them , next time the guy charges it, have him put o-ring caps on it.

Like anything else, it's way more profitable to replace rather than repair. Consumers are conditioned to spend thousands on a new HVAC system - and it's much easier to swallow that than the few hundred here and there nickel and diming you get on maintaining one.

So Indy, you simply added a rubber o-ring to the inside of the valve cap and that did it?! I was thinking you somehow added it to the valve insert. Just wanted to be clear, you didn't have to unscrew the insert of the valve, simply the external cap?

So I guess if you ever have the system emptied for any reason, then you would replace the valve insert. I don't suppose there would be anyway to do that w/o letting all the freon out.

Just for grins, what is the recommended pressure for the low side and high side? I did some work w/ A/C in another life, but don't remember what pressure we considered "normal". Does it vary with the system brand and type these days? My work was at a very large garden style apartment complex that had identical units.

WalMart sells chrome plated brass Shrader caps with rubber seals in them. I use them on all the tires in the family. A 5-pack runs a couple of bucks.

I didn't remove the schrader valve - that would involve either pumping down the system or leaking a bunch of refrigerant (which is illegal).

No I just took out my handy o-ring kit, found one that fit inside the cap, and tightened it down good. Problem solved.

The pressures vary with the ambient temp and the unit itself, however mine (I have two) run about 75-80 on the suction side and 275 on the high side on a hot day.

You actually use these pressures to figure out the superheat of the system in order to determine the charge.

Auto tire Schrader caps are much smaller than HVAC ones. Also my cars have different connections on the R134 AC system than my house, which uses R-22.

I would say at least a rudimentary knowledge of refrigeration is pretty good to have - we all have refrigerators, and freezers and window units and car units and central air - they all work basically the same way.

Here's a page that'll give you some of the basics.

http://www.inspect-ny.com/aircond/aircond1123.htm

you would be surprised as to how many times the "pros" will simply charge a unit and not investigate the reason behind WHY it lost part of a charge especially when there is significant loss.
keep an eye on the valve caps they will start to leak again.

when looking for a leak, start obvious - look for any oil on the condenser coil (outside unit) bubble testing and "sniffers" work great too.

Indy, good job in finding your problem!! take this with a grain of salt but dont get to "overconfident" with the EPA license. there are alot of things that could go bad in a split system. Guages and beginner knowledge is great to have but STOP if you are unsure about anything.
I speak from 'spierience here - I am NO expert by any means and I will never claim to know more then someone who has been in the field for years.

just throwing it out there.