AC with slow leak

[KC Strip]

I have a 99 Suburban with a slow leak. The problem is that the place I took it to earlier this year couldn't find the leak. They told me I had one because I was virtually out of freon. They replaced the freon at that time, but lately it doesn't seem to be cooling as well as it should. Also, the AC seems cooler on normal vs. maximum/recirculate. Any thoughts or suggestions?

BTW - the condenser is only two years old.

 

[Kestas]

Did they add UV dye during the first service?

The reason it's not cooling properly may be that air is in the system, or the shop didn't charge to the proper level.

 

[KC Strip]

Yes, they used the UV dye.

 

[Kestas]

When a tech "can't find the leak" the usual culprit is the evaporator. This should be verified by looking at the evaporator condensate when the a/c system is working, and see if there is UV dye in the condensate.

 

[milwaukee]

May or may not help but I had a slow leak that couldn't be located in one of my cars and 134a with stop leak fixed it.

 

[hatcoleman]

I WOULD SUGGEST A PRODUCT CALLED SUPER SEAL. I OWN SEVERAL AIRCONDITIONING SUPPLY HOUSES. THIS IS A PRODUCT THAT WORKS VERY WELL. IF IT DIDN'T MY SERVICE TECHS WOULD LET ME KNOW.

 

[daman]

If fixing on your own,

the first thing you need to do is if you still have
a charge(pressure)is rent or borrow a leak detector
(sniffer) and go through out the whole system and find
your leak, once found you need to evacuate the charge
fix the leak then pull a deep vacuum add back into the
system the factory amount of freon and maybe 2-3 oz's
of PAG 150 oil, you'll need a set of gauges and a vacuum
pump to do the job.

i do all my own AC work been doing it for years do it
right and do it once.

i would look for a new shop also..

 

[daman]

Forgot don't use any type of stop leak in auto AC systems
i slimes up the internals and doesn't work.

 

[daman]

Article is in an Adobe Acrobat PDF file.

http://www.motor.com/MAGAZINE/Pdf/042003_04.pdf

 

[milwaukee]

Quote:

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Forgot don't use any type of stop leak in auto AC systems
i slimes up the internals and doesn't work.

---

It worked just fine for me.

 

[daman]

Quote:

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Quote:

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Forgot don't use any type of stop leak in auto AC systems
i slimes up the internals and doesn't work.

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It worked just fine for me.

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stop back in in a season or two and post how it's doing,
plus if you now take that to any reputable ac shop they
will not touch your car with that ____ in it, it messes up
very expensive recovery machines, good luck!!!

 

[KC Strip]

Thanks for the advice everyone - it is appreciated. I'll keep you posted as to what happens.

 

[milwaukee]

Quote:

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Quote:

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Quote:

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Forgot don't use any type of stop leak in auto AC systems
i slimes up the internals and doesn't work.

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It worked just fine for me.

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No problem. Thanks for advising me to spend $600 on a $900 car. Sounds like a auto tech to me.

Stop leak worked for me.


stop back in in a season or two and post how it's doing,
plus if you now take that to any reputable ac shop they
will not touch your car with that ____ in it, it messes up
very expensive recovery machines, good luck!!!

---

 

[milwaukee]

I am not going to pay $600 to "fix" a slow leak on a $900 car.

Stop leak worked for me.

 

[onion]

"Sniffers" are overrated. They come in handy in certain situations (like the evaporator drain), but for parts of the a/c system that can be accessed without unreasonable difficulty, I prefer soap bubbles. Go to Walmart and buy a garden sprayer and one of those big jugs of bubbles (in the toy department). Spray down all the rubber hoses, especially at the crimps, and all fittings. If you're careful and thorogh, you can detect even very small leaks. Also take a look at the compressor clutch. If you see oily buildup, then there's a good chance that the shaft seal is leaking.

 

[daman]

Quote:

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"Sniffers" are overrated.

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Not by a long shot, you'll never find all leaks like that
hardly any matter of fact, A Halogen leak detector and or
UV dye is the only way you'll find it properly,
just trying to help, i like doing things right and only
doing them once,that's how i was taught when i worked
in the shop long ago, but to each is his own i guess..

 

[onion]

Quote:

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Not by a long shot, you'll never find all leaks like that
hardly any matter of fact,

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That's funny 'cause I've used soap bubbles for many years... diagnosed and repaired dozens and perhaps hundreds of A/C systems. But who am I to question a man who 'does his own work'?

I agree with you on the UV dye.

Leak detectors are mostly a waste of time in my experience... unless you're sniffing them into an area that's difficult to access. Super Bubbles will find leaks that you'll never find with an electronic gadget.

 

[KC Strip]

Some interesting notes ...

1. The accumulator is very hot when running the ac. It is my understanding that this should not be the case.

2. My Suburban does dual cooling and the back cools better than the front.

3. Upon another visual inspection (with the UV detector light), there were no noticeable leaks.

4. The condenser is very hard to see or check. Could this be a problem?

5. What about something inside - like a door or flap not correctly opening?

Just looking for some help before I lay out the big bucks to get it fixed. Feel free to ask any additional clarifying questions.

Thanks!!!

 

[KC Strip]

So the last bit of info I put in scared everyone off? I hope not!

 

[daman]

Did they change your orifice tube?, also replace your clutch on
your engine fan, i see allot of time that's the problem on these trucks ,don't draw proper air flow threw the condenser thus pressures rises and hinders freon flow.

sounds like you need to start all over from scratch, evacuate the system
fix any known leaks,add 3-4 oz's of pag 150, pull a deep vacuum,charge the proper amount of
134 into the vacuum..