A/C leak

[ravenpower]

Hi,
I own a '84 Carrera 3.2 ad in the last 2 yrs I did try to let my a/c to work for more than one month.
When the system is full it works good, but then it starts to get warmer until nothing.
The a/c has been serviced with new oil and R12 substitute gas ( R414 ? )with dye added in order to find the leak.
We did check all the system parts and we can't find any leak according uv light.

Any suggestion?

[wayne robson]

Hi ravenpower, on 84 the receiver drier is up under drivers wheel arch, when re charging
should always fit new drier,especially if it leaked before letting air in,also because of the driers position check oring connections in and out of drier,best to fit new orings on connections.Pelican sells a good , not expensive drier for under $40.00.

[GH85Carrera]

The original hoses are not barrier hoses. They are actually not designed to prevent leaks. The gasses just ooze out through the rubber hoses. If it only lasts one month you likely have another leak as well. Step one is check every single connection and the compressor nose seal. I usually pressurize with nitrogen and uses soapy water to look for bubbles. If you still are having leaks you have some decisions to make.

It is dirty work but not real difficult to remove all the rubber hoses and replace them with new barrier hoses. That is what stopped my leaks. I used to recharge every single spring. I switched out to barrier hoses and the leaks stopped completely.

You can pull the current hoses and just keep good notes and take lots of pictures and take those hoses to a local AC shop and have them make you new hoses or just buy all new hoses from Pelican. That is what I did.

And the most important thing it to completely ignore the advice from one person sure to respond. He will tell you the hoses don't leak. He is just flat out wrong. He is like a flat earth believer. He will ignore the advice of all the other members and professional and continue to post his wild theories. Just ignore him.

[Discseven]

Raven... from your description it sounds like a leak. My input is a sniffer is more reliable / dependable than UV. One might miss a visible signal whereas the sniffer (in still air) will pick out a leak one might not be able to see.

Also... we are assuming you are speaking of a cold-to-warm transition over several operating hours. If this happens within a few minutes, and does so every time you operate the AC, it might be the reeds in the compressor are in backwards. I've heard that reeds installed backwards will fail to work after a short time of operation.

CIAO!

[DRACO A5OG]

Check the fill valves, mine was leaking from the high side. I found the valve was loose as a result when I screw the cap on it would push down on the needle resulting a slow leak. Tightened it, no more leaks. I use ES12a.

[wwest]

Originally Posted by Discseven

Raven... from your description it sounds like a leak. My input is a sniffer is more reliable / dependable than UV. One might miss a visible signal whereas the sniffer (in still air) will pick out a leak one might not be able to see.

Also... we are assuming you are speaking of a cold-to-warm transition over several operating hours.

Good point.. more detailed description would be helpful.

If this happens within a few minutes, and does so every time you operate the AC, it might be the reeds in the compressor are in backwards. I've heard that reeds installed backwards will fail to work after a short time of operation.

CIAO!

If Discseven is correct, then it is entirely possible that your evaporator is freezing up.

1.) The full CW position of the cooling level control thermostatic switch often results in evaporator freeze up due to drifting out of calibration over time.

2. A stuck/sticking thermostatic switch is a rather common failure which would definitely result in freeze-up.

3.) Loss of the gas charge within the thermostatic switch capillary tube is also somewhat common and will result in freeze-up.

Most, if not all, aftermarket A/C product vendors will always recommend, as does the EPA, the addition of a high pressure switch when retrofitting to R134a.

Absent improving the factory condensing capability the R134a refrigerant charge will operate at significantly higher pressures vs with R12. Back the era of these designs it was common for the design to include a ~500 PSI HPRV, High Pressure Relief Valve, to vent the R12 to atmosphere in the event that system pressure rose that high.

Obviously with R134a the probability of the HPRV reaching "blow-off" level is higher.

Luckily the pressure switch has 2 elements.

[GH85Carrera]

Read the first post. He is NOT using 134a. He is using something called R414 which I would GUESS is not legal for automotive use. He has a leaky system that is using propane I suspect. I am too lazy to Google R414 and find out what it really is. Personally using a leaky system filled with propane is something I would never try for any amount of money.

[Bob Kontak]

Originally Posted by GH85Carrera

Read the first post. He is NOT using 134a. He is using something called R414 which I would GUESS is not legal for automotive use. He has a leaky system that is using propane I suspect. I am too lazy to Google R414 and find out what it really is. Personally using a leaky system filled with propane is something I would never try for any amount of money.

NRI - Refrigerants

http://www.icorinternational.com/images/r12_hs_hs2.pdf (being phased out)

[RedCoupe]

While I was eating my lunch, I googled R414 and found this:


HCFC - R414B

A blend of R-22, R-124 and R-142b with hydrocarbon R-600a (isobutane) added to improve mineral oil miscibility. This blend can be used to retrofit R-12 automotive air conditioning systems as well as stationary refrigeration systems. The pressure and system capacity match R-12 in 45F to 50F evaporators, and the discharge pressure in hot condensers is only 5 to 10 psi higher than R-12 (a benefit in automotove AC and warmer refrigeration environments). The temperature glide runs about 13F in the evaporator. The addition of isobutane to this blend significantly improves mineral oil compatibility, particularly for high viscosity oils used in auto AC.

A refrigeration supply site listed R414B as ASHRAE rated A1 which they said meant Non-Toxic and Non-Flammable.

[tirwin]

Originally Posted by wwest

Maybe it's just "misery loves company", owners SUCKERED into buying SNAKE OIL from a disreputable vendor.

You are so much chomping at the bit for any and every opportunity to bash one vendor that you completely disregard the details of the post.

The only one around here that is disreputable is YOU and you keep digging the hole deeper every day with crap like this.

Ignore wwest.

[wwest]

Originally Posted by GH85Carrera

Read the first post. He is NOT using 134a. He is using something called R414 which I would GUESS is not legal for automotive use. He has a leaky system that is using propane I suspect. I am too lazy to Google R414 and find out what it really is. Personally using a leaky system filled with propane is something I would never try for any amount of money.

Sorry, you are correct, I took "( R414 ? )" as OP being doubtful enough that he could have meant the much more common R134a retrofit.

Now that I know that such a thing as R414 even exists....

Leakage rate unknown.....

[Ronnie's.930]

Originally Posted by tirwin

The only one around here that is disreputable is YOU and you keep digging the hole deeper every day with crap like this.

Ignore wwest.

Very eloquently put, Tim (and spot on, too)!

[Bob Kontak]

Originally Posted by wwest

*** No, it is not really me that has concluded that our legacy non-barrier hoses do not leak.

Do you have the link to the EPA white paper? I swear you posted it once. I can't find it from Google searches and I do see plenty of info where it's stated the non-barrier hose is meant to leak in high pressure situations. Interested in where that designed leak point is. (I am sure this has been discussed here but would like to read it for myself)

Also, the system your 92 Aerostar has/had to allow "blow" off R-12 in high pressure situations.. What is that called? EDIT: Found it above HPRV.

[Bob Kontak]

Originally Posted by Discseven

Raven... from your description it sounds like a leak. My input is a sniffer is more reliable / dependable than UV. One might miss a visible signal whereas the sniffer (in still air) will pick out a leak one might not be able to see.

Also... we are assuming you are speaking of a cold-to-warm transition over several operating hours. If this happens within a few minutes, and does so every time you operate the AC, it might be the reeds in the compressor are in backwards. I've heard that reeds installed backwards will fail to work after a short time of operation.

CIAO!

I am assuming 1/2 hour. Need clarification. Could simply be an overcharge of refrigerant causing freeze.

Also, from a re-read of original post, it may take a month to get warm? ravenpower needs to be specific about how long before it gets warm.

[DG624]

The original hoses are not barrier hoses.

This is why I don't use my AC...I was also told that different refrigerant would not leak but I have not used my AC since I bought the car in 98. My AC never really worked... poor cooling. I would like to see a more efficient system that is smaller and lighter and does not cause bad environmental side effects.

[wwest]

Originally Posted by Bob Kontak

Do you have the link to the EPA white paper? I swear you posted it once. I can't find it from Google searches and

I do see plenty of info where it's stated the non-barrier hose is meant to leak in high pressure situations.

Link(s)?

Interested in where that designed leak point is.

You can be sure that it's in the 400-500 PSI range.

(I am sure this has been discussed here but would like to read it for myself)

Also, the system your 92 Aerostar has/had to allow "blow" off R-12 in high pressure situations.. What is that called? EDIT: Found it above HPRV.

Guidance on Retrofitting to HFC-134a | Ozone Layer Protection - Regulatory Programs | US EPA

ProAviation(.com) Professional Aviation Associates has adopted the EPA R134a retrofit procedure.

http://proaviation.com/wp-content/uploads/2014/01/ConversionAir-brochure-R134a-pres.pdf

Aerostar had a ~500 PSI HPRV built into the back of the A/C compressor.

[Bob Kontak]

Found the same link from early 2008 in Pelican. Jim Sims posted it. See post #25.

Barrier hose vs non-barrier hose.

The links I have are from "forums". They include a brief description of the concept but no testing. No need to bother as you understand the concept and they (the posts) are easily refuted given the EPA findings.

There is one argument I will use that seems valid. The EPA says that early tests found unacceptable leakage in non barrier hose. Later tests showed that it was ok because the "oil used in AC systems" plugged up the holes?

That is the extent of the data. What did they do differently? What did they do in the first test?

This is enough on this topic as we have veered off course. Non barrier hose will not bleed off R124 OR R414B in a month so this is a separate topic. Thanks for the link!

[wwest]

Originally Posted by Bob Kontak

Found the same link from early 2008 in Pelican. Jim Sims posted it. See post #25.

Barrier hose vs non-barrier hose.

Post #28 I find MOST interesting...

The links I have are from "forums". They include a brief description of the concept but no testing.

There is one argument I will use that seems valid The EPA says that early tests found unacceptable leakage in non barrier hose. Later tests showed that it was ok because the "oil used in AC systems" plugged up the holes?

That is the data.

It makes sense that the leakage rate of our legacy non-barrier hoses would be pressure related, simulate the "blow-off" function of the HPRV.

The other thing is that there seem to be numerous instances wherein modern automotive A/C systems continue to non-barrier hoses.....

Pressure, enough pressure, expands the hose thereby opening the tiny slits.?

[Bob Kontak]

Originally Posted by wwest

It makes sense that the leakage rate of our legacy non-barrier hoses would be pressure related, simulate the "blow-off" function of the HPRV.

The other thing is that there seem to be numerous instances wherein modern automotive A/C systems continue to non-barrier hoses.....

Pressure, enough pressure, expands the hose thereby opening the tiny slits.?

Post #28 - Is that they guy who went several years - three - without a top off (well, a mini top off) with non-barrier hose? Bummer the guy did not say where he was based. Nova Scotia vs Phonix, if you know what I mean.

Maybe the EPA tested new non barrier hose vs. old "seasoned" with oil in round one? We don't know. Maybe pressures were different?

These hoses are approaching 40 years old. They do leak at some pressure point - let's assume fact based - by design. They are also really, really old. If it were aircraft, they would have been replaced five times by now.

My spouse has info on that. The T-Rex of ill-timed jokes, from Rockwall. He would know about hydraulic line change intervals on fixed wing aircraft.

[Bob Kontak]

Originally Posted by DG624

The original hoses are not barrier hoses.

This is why I don't use my AC...I was also told that different refrigerant would not leak but I have not used my AC since I bought the car in 98. My AC never really worked... poor cooling. I would like to see a more efficient system that is smaller and lighter and does not cause bad environmental side effects.

Or you could get yours working properly. Drive up to Akron. I'll make a difference or work is free. Beer on you.

I am serious. Early on a Saturday. One man shop.