Sorry...AC hose question

[88911coupe]

Apologies if this has been addressed but I did a search and cant' find an answer. I have an '88 Carrera with an additional condensor/fan in the wheelwell (no name brand) and a Procooler so my hoses aren't "factory", to say the least. I'm also using envirosafe rather than R12 or R134 but not sure sur that matters to my question.
I have considered replacing the hoses but now I'm wondering what would the benefit actually be? I've never had any sort of compressor blow up and the system has only been opened when I added the procooler and condensor, afterwards vacuumed down and could not find any leaks (lucky I guess). I also ran some denatured alcohol through a couple of the longer hoses and got some oil out but it did not seem terribly dirty...also used new oil.
Is there anything wrong with keeping the old hoses, which obviously had R12 for many years? Yes, I know they are not "barrier" hoses but other than a potential for very slow leakage are there any other downsides?
The problem is I can't buy a hose set from the many good vendors who sell them since I'd have to hack them up to fit my current configuration.
Thanks,

[SilberUrS6]

I'd bet that Griffiths Tech could make you a set of barrier hoses if you wanted them. Call Charlie over there and ask. Doesn't hurt to ask.

[88911coupe]

Thanks, I guess I could pull it all out, measure everything and then find someone here in Dallas to make them but my real question is what, if any is the benefit? I'm really trying to avoid creating solutions for problems that don't exist....

[brads911sc]

you can go to a local hose shop. they will have the ends on site and the right hose. if you have no leaks then perhaps you just wait. if you find yourself adding refrigerant every year then worth the effort to repair it.

in houston i use this company... http://www.houstonhose.com/about-us/

I am sure there is a similar one in dallas.

[wwest]

Originally Posted by 88911coupe

Apologies if this has been addressed but I did a search and cant' find an answer. I have an '88 Carrera with an additional condensor/fan in the wheelwell (no name brand) and a Procooler so my hoses aren't "factory", to say the least. I'm also using envirosafe rather than R12 or R134 but not sure sur that matters to my question.
I have considered replacing the hoses but now I'm wondering what would the benefit actually be? I've never had any sort of compressor blow up and the system has only been opened when I added the procooler and condensor, afterwards vacuumed down and could not find any leaks (lucky I guess). I also ran some denatured alcohol through a couple of the longer hoses and got some oil out but it did not seem terribly dirty...also used new oil.
Is there anything wrong with keeping the old hoses, which obviously had R12 for many years? Yes, I know they are not "barrier" hoses but other than a potential for very slow leakage are there any other downsides?
The problem is I can't buy a hose set from the many good vendors who sell them since I'd have to hack them up to fit my current configuration.
Thanks,

Other than the potential for very slow leakage there appears to be only one downside. Unless you have one already you really do need to install a binary pressure switch to control and protect your compressor.

You already have the "required" extra condensor cooling fan that can be used to alleviate the slow leak concern. So the simpler approach might be to add a trinary pressure switch to power that fan 24/7, whenever the system pressure threatens to rise above the design specifications of even the older "non-barrier" type hoses.

[neilschelly]

If your system can hold a vacuum and has no leaks, what are you trying to fix with new hoses?
-N

[Tigerrat]

If you do decide to have new ones made up, take/ship the old hoses so the angled connectors get clocked correctly.

If the system has been together for several years and the temps and pressures are still fine, I would resist messing with it. Ken

[88911coupe]

Ken and Neil...you're basically asking what I'm asking. It sounds like there's no harm in leaving my old hoses in place even if I switch to R134...

[wwest]

Originally Posted by 88911coupe

Ken and Neil...you're basically asking what I'm asking. It sounds like there's no harm in leaving my old hoses in place even if I switch to R134...

According to testing done by the Scientists at DuPont laboratory, and supportrf by statements from the EPA and SAE, your legacy hoses have been permeated by the lubricant used with the old R-12 refrigerant and as such will not leak the R-134a refrigerant.

But.

The factory Porsche design has failure modes, relatively common failure modes, that become of greater concern with R-134a than was with R12. That's because R-134a operates, typically, at higher condensor pressure levels, ~450 PSI, vs R-12.

The most common failure, by a large measure, is the thermostatic switch used to control the cycling of the compressor. This device has been noted to have at least 3 failure modes.

1.) Contacts "welded" together due to millions of inductive "kick" electrical arcing over the working life of the switch.

2.) Loss of the gas pressure within the capillary sensing tube resulting in improper adjustment to attain cooling, basically an "over-ride" of the capillary gas function.

3.) Misguided or inadvertent maladjustment of the capilary tube in an effort, typically, to attain a higher cooling level.

Any one of those would likely result in over-pressurization of your legacy hoses.

So along with the conversion to R-134a the installation of a binary, hi/lo, pressure switch to control (over-ride the thermostatic switch as/when needed) and protect the compressor. (prevent the compressor from operating if the refrigerant charge is to low.) is required by the EPA, and recommended by ALL.

My recommendation is to go ahead and install a trinary pressure switch.

[brads911sc]

my recommendation is to ignore anything WWEST says. Most (99%) has been false.

That said, if they werent leaking, I would leave them. You may find that with R134 you develop a leak that didnt exist with R12. at this point replacement will be needed. Many will advocate just changing them so you dont need to open it up again. Guess it just depends how deep your wallet is since youll end up buying new dryer.

[VW_NUTT]

WWest: that's by for the furthest from the truth about R12 and R134 you can be. If you care to look at the pressure/Temperature chart for both of these refrigerants you will see that they are very close. The manufactures of the refrigerants have to make the P/T as close as possible for the new refrigerants to the old refrigerants. Dupont cant just blend up some chemicals and say here use this now. The compressor is designed to handle refrigerant vapor at a specific density. Normal condensing temperature for most refrigerants is 110*F. R12 @ 110*=135 psig, R134a@110*F=145psig. Just change your oil to the new POE oil change the receiver/drier pull a good vacuum using a micron gauge if you know someone who has one. Charge it up with 134a and enjoy your cool air. I don't even know if my A/C works in my car, I have never tried it. It is like my radio. USELESS! I am an Industrial refrigeration mechanic.

[kuehl]

Originally Posted by 88911coupe

I have considered replacing the hoses but now I'm wondering what would the benefit actually be?

Replacing the old hoses with barrier hoses will reduce refrigerant leakage; non barrier hoses permeate any kind of refrigerant, so ... replace the hoses with barrier hoses; replace o-rings too naturally, and you will have to add a few ounces of refrigerant oil to replace the oil that was lost in the old hoses you are removing.

[kuehl]

Originally Posted by VW_NUTT

WWest: that's by for the furthest from the truth about R12 and R134 you can be.

Lol. Oh, that was just a little bitty snake oil.

[SilberUrS6]

Originally Posted by kuehl

Lol. Oh, that was just a little bitty snake oil.

literal-LOL

[wwest]

Originally Posted by VW_NUTT

WWest: that's by for the furthest from the truth about R12 and R134 you can be. If you care to look at the pressure/Temperature chart for both of these refrigerants you will see that they are very close. The manufactures of the refrigerants have to make the P/T as close as possible for the new refrigerants to the old refrigerants. Dupont cant just blend up some chemicals and say here use this now. The compressor is designed to handle refrigerant vapor at a specific density. Normal condensing temperature for most refrigerants is 110*F. R12 @ 110*=135 psig, R134a@110*F=145psig. Just change your oil to the new POE oil change the receiver/drier pull a good vacuum using a micron gauge if you know someone who has one. Charge it up with 134a and enjoy your cool air. I don't even know if my A/C works in my car, I have never tried it. It is like my radio. USELESS! I am an Industrial refrigeration mechanic.

Kuehl, stand up for me on this one..?


Read just three lines of the 3rd paragraph..


AIR CONDITIONING HELP HOME PAGE,a/c,ac,air,air conditioning,barrier hose,Behr,Bosch,compressor,compressors,condensers, condenser,condensors,drier,driers,dryers,evaporato r,evaporators,freon,Griffiths,improvements,Kuehl,N ippondenso,Porsche,r12,r134a,San

[wwest]

Originally Posted by kuehl

Lol. Oh, that was just a little bitty snake oil.

Yes, and directly from the "mouth", as it were, of the leading A/C snake oil salesman.

Kuehl, apparently, will go to ANY lengths even DISAVOW his own words, to belittle someone....

[88911coupe]

Thanks for the comments, I guess I can keep them for now. What has me a little confused is that it's overall performance is still a little underwhelming. I have to clarify that in early spring there was a small leak that required snugging up a connector. I put the gushes on it and was getting 17/175 which is obviously undercharged, however in checking the P/T charts that should result in really cold evaporator temps and icing but I'm only seeing 40 degrees at the vents with a temp drop of about 20 degrees from the intake air.

[wwest]

Originally Posted by 88911coupe

Thanks for the comments, I guess I can keep them for now. What has me a little confused is that it's overall performance is still a little underwhelming. I have to clarify that in early spring there was a small leak that required snugging up a connector. I put the gushes on it and was getting 17/175 which is obviously undercharged, however in checking the P/T charts that should result in really cold evaporator temps and icing but I'm only seeing 40 degrees at the vents with a temp drop of about 20 degrees from the intake air.

Fan/blower speed..??

Ignoring that question for the moment...

At 40F vent temperature you have probably "hit the wall", the TXV is regulating/limiting the evaporator core temperature to just above freezing, assuming it is operating properly.

You may note the confusion some of us are voicing regarding the oftentimes posting pictures displaying vent temperatures just above, at, and even below freezing. Those are undoubtedly, IMO, the result of someone "monkeying" with the factory settings, calibration, etc.

I suspect we would all welcome anyone to explain, fully explain, those freezing or below vent temperatures.

[88911coupe]

Full cold setting fan on high, just seems like I should be seeing lower temps at the vents. Not really an issue now but we're expecting near 100 degrees this week...typical Dallas summer. Is it possible I need a new TXV?

[kuehl]

Originally Posted by wwest

Kuehl, stand up for me on this one..?

Read just three lines of the 3rd paragraph..

Well Wwest, right now I'm standing up under my car bolting the engine back in.
Want to race?

But, I'm glad you are finally reading, keep up the posts, I like the SEO.