A/C question

I will try to find somebody with this "sniffer" type detector, and tell them what you said. If they say that they found a leak for sure, I would feel much better about them getting in there and changing out the evaporator.

If they don't find a leak, what other possible problems might cause a system to act this way?

I will try to find somebody with this "sniffer" type detector, and tell them what you said. If they say that they found a leak for sure, I would feel much better about them getting in there and changing out the evaporator.

If they don't find a leak, what other possible problems might cause a system to act this way?

so why go through the trouble to begin with? if you have the "big dog" (and youll HAVE to at some point before charging the system), why bother with a makeshift system just to see if it will hold the vacuum? besides, with proper equipment (a 2 stage vacuum pump) its pointless to bother with an overnight pull. a quality vacuum pump will pull it down just as hard in 15 minutes as it will in 24 hours.

it may produce more vacuum than the newer compressors, but it will _never_ produce anywhere near the 500 micron target which is required to pull out all the moisture and non-condensables. there are a _lot_ of home remedies that might get you by, but this is what makes the difference in 45 degree vent temps and 55 degree vent temps. having the proper tools makes the difference in a 3 year expected service life, and a 15 year service life.

if its 101 degrees out and you dont have any money i guess you do what you gotta do to get by. hell, i ran propane in my camaro a/c system when i was

17 lol. but in hvac/r there is no short-cut, and no way to save any money if you want to consider it fixed right.

because in central IL in August, you may have 2 or even three jobs going at once..............

I can 'test' one while I pump the other and charge a third

I never said there was, and I fix it right

if the compressor is cycling on and off, chances are the system is low on refrigerant. honestly i probably wouldnt bother with getting the leak fixed just yet. wal mart sells the quick charge 134a systems for about $8. they also sell a color coded gauge for $9 that will tell you when youre properly charged (points at green). pick up 1 of each, run your system, and add 1 can then check it with your gauge. if its a small leak, that $8 charge might get you by for a couple years. if the leak is very small i wouldnt bother with the expense of fixing it. throw $8 in it every couple years and dont think about it anymore.

slow leak around the compressor shaft

rock chip nicked the condenser

any and all connections should be suspect, especially if you see an oily film around them

ALRIGHT!!!

For now... I am finally cool!

Can I really expect this bliss to last? (Probably not)

I added about half a can and the A/C works great.

I guess if I have a leak, it will stop working. I also guess that if the leak is slow enough I will have saved myself about 1500 bucks thanks to you guys and your patience.

let me know where to send the bill. :-)

Yup I believe he is still the idiot though. I know more self taught people that know far more than formally taught person. It has to do with getting the books and reading them and also a person's ability to understand also with common sense which most people do not have.

So how HARD is HARD (atmospheres) ?

I think you have better find one and try it before you say that pulling that little bit of extra vacuum will product a colder vent temp. So how many atmospheres does one of these super vacuum pumps pull ?

I have found that when a HVAC system has really failed it should just simply be replaced with a completely new system. It ends up being the overall cheapest way to do. Usually the new system is so far more efficient that it will pay for itself in a couple of years.

>

I think you got it that is if it will hold for a least 9 months. Just remember all compressors will leak some so having to add a little every so often is not a problem.

Surfersabo wrote:

The amount of pressure you have in system depends on the tempature of the system but this is not a accurate test always because as long as there is enough freon in the system to keep some liquid under pressure the pressure will be at a constant vs tempature. The real "test" of a charge state is when it is running and tempature and humidity is factored in. It is not cut and dried as some would lead you to believe.

Been doing this for years. My recovery system is a tub of ice and a Freon cylinder. Yes, it's slow. Yes, it does not remove every bit of Freon. But it does get all the liquid so you're not releasing much. As far as a vacuum pump. I use an old refrigerator compressor. They way you get the moisture out is you pull a vacuum. Wait to see if it leaks. Might have to do this a few times as Freon hides in the oil and takes a while to come out. Then you add a bit of Nitrogen, about 3 PSI. Wait a while and pull vacuum again. The Nitrogen will get the moisture out. While you're pulling vacuum the last time heat the receiver/dryer with a hair dryer. Before you ask, we have race cars that we use Nitrogen to control the throttle so we always have it. But, it's not hard to get and if the system has not been exposed to air a long time you can skip using it.

Al

you will NEVER under the best of circumstances achieve anywhere near (not even close) to the 500 micron target with a refrigerator compressor. you might think it works great for you and thats fine and well but dont mislead others into thinking your way works because it doesnt. it might enable you to get cool air from your vents but its not as cool as it would be if it were done right.....and your components wont last as long as they should. you arent pulling a deep enough vacuum to evacuate all moisture and non-condensables. sure it might get you by and im not busting your chops on this. i just dont want others to think this is an accepable alternative.

Hey Nate, where do you get your vacuum pump oil?

i buy it in bulk at johnstones here in billings. i buy in bulk because i change the oil in my vacuum pump after _every_ usage as recommended by my vacuum pump manufacturer. this is why i attach a $5 vacuum pump charge each time i use it (although most companies charge 15).

why?