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Topic: Queastion about AC system mechanic SNAFU (Read 2364 times) previous topic - next topic

Queastion about AC system mechanic SNAFU

when I had the AC system upgraded and flushed/upgraded to the new non damaging cooling rs232(??) I has a nasty issue start.

It seems that when the 'professionals' I went to to have the system flushed and recharged *cough*jiffy-lube*cough*, they managed somehow to let the chemicals 'mix', this now has caused me no end of issues with my AC system, because as I've been told by a very good mechanic that those 2 chemicals mixing would turn the inside of my ac hoses to jelly.

of course the place i went tells be that it is Impossible for this to have happened and are taking no responsibility for their mistake. Basically I've been told i need to replace all hoses (which are not available on the market easily) and/or the compressors as well, etc to make sure that all mixed chemicals are removed or this will keep happening.

Queastion about AC system mechanic SNAFU

Reply #1 –
The parts are widely available, and fairly cheap.  R-134a (what they would have put in) would not have reacted with any R-12 (what your car came with) as there is no way to connect an R-134a machine to R-12 lines without installing adapters, and you can't install adapters without removing the valve cores.  You can't remove the valve cores without any R-12 still in the system venting out.  Placing that aside, you have to vacuum the system before you can charge it. 

Refrigerants are not mixed in your system. 

What MIGHT be mixed in your system is the lubricant.  R-12 systems used mineral oil, while R-134a systems use a synthetic PAG oil.  The 2 should not mix, they are known to become semi-solid and move through a system as millions of round goo-pellets (bad).  If this happens, many parts will have to be replaced, only because you can never get all the  out.  Now, when you look at a complete R-134a system for Mustang (which means for Fox T-Birds and Cougars as well), at LateModelRestoration, for example, you'll be seeing parts such a thermal barrier hoses, more efficient condensers and updated compressors.  All of it adds up to a R-134a system that performs as well as the original R-12 one.  A retrofit can never reach the performance of R-12, the parts just aren't as efficient at what they do. 
If you do have gel happening in your system, you're probably better off buying the kit from latemodelrestoration.  If you don't have mixed oil or if the retrofit kit used ester oil (compatible with R-134a refrigerant, and safe with mineral oil), then you need to keep looking for your real problem.  Also, Jiffy Lube won't know this, but when doing a retro from 12 to 134a, the clutch cycling switch needs to be adjusted to disengage the clutch at a lower pressure.  I set them to 22-25 psi, the adjustment screw is visible with the switch unplugged.

Queastion about AC system mechanic SNAFU

Reply #2 –
And the good thing is, with the LMR kit, you can install it all, then take it to a place that specializes in vehicle AC systems (maybe not the stiffy lube place ;) ) and simply have them fill and adjust the switch as Foe mentions...easy stuff.

All you'll need are the fuel line disconnect tools available at an Oreilly or Autohole store. (I've got the cheap plastic set, and they've held up to over 6 years of use, off and on..)
'98 Explorer 5.0
'20 Malibu (I know, Chevy, but, 35MPG. Let's go brandon, eh)

Queastion about AC system mechanic SNAFU

Reply #3 –
Ok, so last year I had the AC on my 86 5.0 rebuilt to the newer 134a.  It has been to the shop 3 times since then to have it repaired again because it keeps leaking.  Now fresh out of storage for the winter, she don't work again.  I'm personally ready to pull the plug on them and just bite the bullet and have the system redone again since they obviously can't find why it is leaking.  New compressor, dryer, high and low pressure lines.    I looked at LMR like was mentioned above.  They have a full rebuild kit.  1982-86 Ford Mustang 5.0L Air Conditioner (A/C) Conversion Kit, R-12 - R-134 - Fox Body.  part # HW-19712C.    Your saying that this kit will "plug and play" so to speak.    I really want this to work again properly and have grown tired of the excuses as to why the system is dead again.  Sure they keep fixing it and it doesn't cost me but when is enough enough.  They clearly are as stumped by the problem as I am frustrated with it.

Go Fast the first time.  The tickets the same.
86 Thunderbird 5.0.  All original good weather driver. Tbird Reg #53035
86 Thunderbird TC.  All original good weather driver.  Tbird Reg # 58555
87 Thunderbird TC.  All original good weather daily driver.  Tbird Reg # 64647

Queastion about AC system mechanic SNAFU

Reply #5 –
Quote from: mbrooks;433156
when I had the AC system upgraded and flushed/upgraded to the new non damaging cooling rs232(??) I has a nasty issue start.

It seems that when the 'professionals' I went to to have the system flushed and recharged *cough*jiffy-lube*cough*, they managed somehow to let the chemicals 'mix', this now has caused me no end of issues with my AC system, because as I've been told by a very good mechanic that those 2 chemicals mixing would turn the inside of my ac hoses to jelly.

of course the place i went tells be that it is Impossible for this to have happened and are taking no responsibility for their mistake. Basically I've been told i need to replace all hoses (which are not available on the market easily) and/or the compressors as well, etc to make sure that all mixed chemicals are removed or this will keep happening.
Sounds like your 'professionals' don't know their heads from their rears. Mineral oil (R12), Ester oil (R134a/R12), and PAG (R134a) oil are all fine together. The chlorine from R12 can react with some brands of PAG oils to create hydrochloric acid, which is why I'd recommend running Ester oil in a conversion or flushing and then using PAG. You should flush the system anyways because leftover mineral oil isn't miscible with R134a, so it just sits in your system taking up space and reducing performance.

What exactly is going on?

Queastion about AC system mechanic SNAFU

Reply #6 –
Quote from: TheFoeYouKnow;433190
Has your guy installed UV leak detection dye?

Yes he did.  First time it was an O-ring he forgot.  Second time it was coming from the low pressure side of the compressor I believe.  Third time was from the fitting at the dryer.  Now I'm wondering what it will be this time.

Go Fast the first time.  The tickets the same.
86 Thunderbird 5.0.  All original good weather driver. Tbird Reg #53035
86 Thunderbird TC.  All original good weather driver.  Tbird Reg # 58555
87 Thunderbird TC.  All original good weather daily driver.  Tbird Reg # 64647
 

Queastion about AC system mechanic SNAFU

Reply #7 –
There is a reason a retrofit kit comes with about a pound of different o-rings, they're meant to all be replaced as part of the procedure.  Some guys don't, I do.  It costs me money to have to continually chase leaks on a car.  That and it makes me look bad.