Air-cond. leak: where likely on low-mileage '99 Trans-Am ?

[BobbyGFirebird]

My car had compressor not spinning for over a year or due low-coolant, but worked fine when I filled up with 143a last month. It loses it slowly over a few weeks, but no smell in the cabin. Is there a likely culprit on these low-mileage Trans-Ams?

I know I can do the dye test, but wondering if you smart F-Body dudes can direct me to whether likely the compressor or a common hose that goes? Will filling a few times with AC Pro Cold fix the small leak, or do I need to use a Stop Leak kit ? thks

[SMWS6TA]

Dye test is your best bet, other wise listen for obvious leaks. Now if you had a Freon detector that would zero in on it for sure.

I just dropped $1280 on my sons car fixing his because the evap core split then found out the previous owner drove a screw into the condenser.

[GULLETT17]

Go ahead and put dye in it, but I always suggest starting by swapping the Schrader valve.

[BobbyGFirebird]

Schrader valve where you put the Freon 143a refrig. in? I wonder if a metal cap would work just as well if that's an obvious leak point? I did see that the hoses are not oily or obviously dripping. Luckily, today was cool enough I was thinking about heater more than the A/C which at least now has refrig. / sealant running thru it to get it and the compressor thru the winter.

Is there an Autozone or similar product with red dye I can see with naked eye, or do I need buy a UV light ? Thanks guys.

Go ahead and put dye in it, but I always suggest starting by swapping the Schrader valve.

[pajeff02]

UV dye is what you want. They sell the UV flashlights for less than $15 and they work great. You will need to open the system to pour some dye into a hose unless you have the tools to inject it through the port. You're not around Elmira or Corning by chance, are you? I have all the stuff to work on AC systems and enjoy a challenge.

[GULLETT17]

Schrader valve where you put the Freon 143a refrig. in? I wonder if a metal cap would work just as well if that's an obvious leak point? I did see that the hoses are not oily or obviously dripping. Luckily, today was cool enough I was thinking about heater more than the A/C which at least now has refrig. / sealant running thru it to get it and the compressor thru the winter.

Is there an Autozone or similar product with red dye I can see with naked eye, or do I need buy a UV light ? Thanks guys.

Yes. I'm not sure a different cap will help. You should be able get replacement schraders at any auto parts store. Let the pressure off the system by pushing in the existing schrader then screw it out to put a new one in. You will obviously need to put a couple cans of 134a back in.

[BobbyGFirebird]

will be Watkins Glen trip next yr. ! Maybe I can buy you BBQ dinner for fixing rhe leak ! In meantime, I'm hoping AC Pro Cold cans with some sealer are slowly plugging some small leaks. Seems to be leaking less.... But we're almost out of AC season anyway. Main goal this month was to ger a charge in there to keep the compressor, clutch and other parts lubed and exercised so wont dry out entirely. A budget-based back to life try!

[pajeff02]

About an hour and a few minutes up the road from our house. Just say the word...

[BobbyGFirebird]

ok Guys, a newbie question, but: most of the lovely "Freon r143a" refrigerant I loaded up so proudly a few months ago has leaked out. So, after a few months of nice A/C, I want to put the red-dye stuff in and see where leaking. Do I need to worry about the dye spraying in to the cabin if the leak is in the Evaporator, or are these leaks more typically the AC pump, hoses and lines under the hood? My car was used for several years with no refrigerant, and thus pump never ran, so likely the seals dried out somewhere in system. Where the likely spots, and do I need UV glasses to see the red dye? Thanks

[SMWS6TA]

Best method would be to use a Freon detector.

Harbor Freight sells them for $70 Item #: 92514

HF might not have the best tools in the world but this should be able to find the leak. I used one to find out it was my son's evap core on his GP.

Dye is mess and not always reliable.

[pajeff02]

I wouldn't hesitate to add dye to the system. My understanding is that many new cars come with dye pre-installed just in case there is a problem.

[BobbyGFirebird]

Gents,
A) for me: When it's very cold out, like around 32deg Fahr. freezing, and you turn the AC on to keep the fluid pumping through for a bit, does it generate enough pressure to really circ it thru system?

B) for a friend with teens driving an old Ford Ranger: when we run the defroster, is that using the AC system ? Other words, if an AC system is NOT working, does that make the defroster process not work as well ?

[SMWS6TA]

A it will run on low pressure till it doesn't have enough to activate the compressor . But doing so like that ends up killing the compressor. Slow leak I would check the valve.

B - no the defrost doesn't control the ac. As long as the ac button is off all your getting is fresh air, even if the temp is on cold. You have to turn on the ac or select it on the dial in order for the system to engage the ac.

[BobbyGFirebird]

OK.... it's warm again and I've topped up the A/C with refrigerant (it never dropped enough to not run compressor this winter, but definitely leaked about 50%, and I added one can with the green dye. Picked up the UV light and glasses for $15. THANKS ! Now, where is most likely culprit on a low-meage T/A WS6? Exame, I've heard Toyotas have leaky condensers....

Any thoughts on likely leak points? System took two 12oz. cans and is blowing cold.

[SMWS6TA]

Check the schrader valve, those usually are the 1st culprits then around any connectors like near the condenser. If know any home HVAC guys see if you can borrow a Freon detector, that will zero in on it fast and better then the dye.

[BobbyGFirebird]

should I try tightening the Schraeder valve with a tool from Auto Parts store... ? No need to relive pressure to do that. I just put 2 new cans of refreig. and dye in there...

(I may have the tool left over from grade school when we used to let the air out of the tires of the mean neighbors...! )

[cornerman]

A it will run on low pressure till it doesn't have enough to activate the compressor . But doing so like that ends up killing the compressor. Slow leak I would check the valve.

B - no the defrost doesn't control the ac. As long as the ac button is off all your getting is fresh air, even if the temp is on cold. You have to turn on the ac or select it on the dial in order for the system to engage the ac.

The A/C system IS used when on the defrost setting, it dehumidifies the air

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[BobbyGFirebird]

Good news: no apparent leaks with UV dye. Will clean schraeder low-pressure port area under cap where I can see bright green dye as that's where it went in. I will wipe that clean to bare metal and see if it goes green in a few weeks. I likely have a slow leak in compressor or condenser, but it's SO easy to put Freon in these days.... not a big deal.

Question: how to tell if the Drier/Receiver is ok? When the system ran dry, as I now know I don't have any BIG leaks, is it likely water and air got in there? Other words, does drier "purge" itself so it doesn't get soaked and clogged? How it works?

[cornerman]

www.airconcars.com

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[cornerman]

http://www.airconcars.com/html/how_it_works.html

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