Getting ready to replace the old York compressor and was debating changing the old hoses out for barrier hoses but then read this on an EPA webpage.

Quote from the section on Hoses and O-rings.

"More recent testing, however, has shown that oil used in automotive a/c systems is absorbed into the hose to create a natural barrier to R-134a permeation. In most cases, the R-12 system hoses will perform well, provided they are in good condition."


Here is the link to the EPA's site on Retrofitting to R-134.
Guidance on Retrofitting to HFC-134a | Ozone Layer Protection - Regulatory Programs | US EPA

Guess I'll test it out and see how long the R-134 lasts before I rip out the old ones.

Scott
_____________
78 SC Targa

LOL, don't pin me down on the old drier blow off valves,
it could (could means not conclusive) have been 450 psi, who knows.

Believe me it won't last not long. We have had many customers (DIY and shops) over the years switch to R134a with stock hoses and only to come back the next year and replace them with barrier.

The original tests on hoses came about with the concern of freon escaping.
So they tested the original non barrier hoses and determined that the hoses leak so many parts per million over a given length at a given temperature and pressure.
The hose mfg's were given the task to reduce the permeation rate and barrier hose was developed.

Logically 'oil' might reduce the permeation rate, the question is by how much.
And understand whom ever reported those results to the EPA in most likely hood
did not test cars with 40 linear feet of barrier hoses. Most of those cars tested were front engine cars which typically had less than 10 feet.

You will also find conflicting information as to whether you can mix PAG with R12 mineral oil. MAC (mobile air conditioning society) ran reports years ago produced by the compressor mfg's on the effect of using mineral oil with R134a, and or mixing PAG with mineral oil. The results were not good; the compressor bores got wiped out and the copper plating on bearings went all over the place. Not a pretty site nor an inexpensive one to fix.
And, our facility has witnessed many not good cases where clients mixed PAG with mineral oil; it produced a sludge in the system =expensive repair.
And on the topic of 'sealants', avoid them. I have seen more cases of sealants crapping up a system and damaging switches... its simply not worth the... if I may SNAKE OIL (thank you Wwest) fix.

Why Wwest. ?

I'm done here gang.

Ditto.

Me too.

The EPA is right. Leakage is negligible for the typical foot or two of hose in most cars. If you have 43-47 feet of hose like (43 in my 911)...then multiply by 43.

The last study I saw cited the non barrier hose leaks about 7 times as much R134 as the barrier...so multiply the 43-47 feet of hose by 7. Perhaps that is still small compared to the cost of hoses if you DIY. If you are paying labor for servicing, along with the time wasted and the R134 itself, it might add up.

Thanks for the entertaining thread! I think I learned something...seriously.

lines
 

I am interested in doing a custom AC application using non factory installed parts / lines on my wide body 74 911s. I have a large factory 930 turbo tail. and am considering hard lines through the passengers floor against the tunnel. Have been breaking quite a few 944 cars lately and have a bunch of parts there. In all my mess I don't see factory running long soft lines in this day and age. Also have a thread on the 997 forum where a guy snapped a image of 99 C4 pan as a guide to current technology.
http://forums.pelicanparts.com/uploa...1365909786.jpg


Since I am not running a tubo have some room for a large condenser in rear and have a few 944 BMW Behr compressors hose ends etc. I really only care if it works for me. This discussion of my vent will be so much cooler than yours is a bit silly so based on that,

I expect 32 deg and I will deliver lots of frozen Ice cream to hot chicks. You guys need to lighten up a bit !
http://pcars.us/albums/6601_porsche_cars.jpg

They are still available and the BO pressure, for the few that I found, varied from 350 to 450 PSI.

YOU would know, if you ever bothered to take the time to provide more exacting information...

Just trolling for comments? You waited 2 days before posting again in this thread? and you were the last one that posted?
Just stop - go play in the sand box and leave us alone!

Trolling, no. Kuehl was so kind as to provide a list of our various posts and I just went through them to see if an update was needed.

So by your standards, since Kuehl provided the list, wouldn'y he be the TROLL?

Question re A/C recharge for 87 3.2
 

Please excuse a new member and older purchaser of the Bird, but this looks to be the best thread to post relative questions. I have the occasional use (I do not complain) of a 1987 GUARDS RED CABRIOLET with a bit over 40K original miles. Perfect car on a second set of tires in practically new shape. Always garaged/locked except when I wax it (Autoglym of England), drive it and hear it SING. I plan to take over ownership of this car one day....Until then, planning a major mileage tuneup. A/C has worked and been recharged several years ago but has dried up since. Is it alright to ignore the A/C, not recharge or check related hoses? Any other major items to watch? The oil return tubes drip a little oil at times and it blows about a quart in a thousand miles which I understand is normal (I've checked and see oil loss is listed on the orig. sticker :) ). Your suggestions below are appreciated - except those stating the bleeding obvious: that I need to drive it a bit more. Thanks!

Disconnect the compressor clutch wire until you can have the system refilled/checked. If you operate the "raw" factory system with low refrirerant charge the compressor might soon be TOAST.

I sense in you are saying in your climate area AC is not needed often?. But, if you want to use it, as it comes in handy for those damp muggy days, I'd suggest as the minimum, replacing all the hoses with barrier hoses, replace all o-rings, add low-high pressure switch, new drier, convert to R134a with ester oil.

If you have a 'black' oil line above the compressor pulley on underside of the engine deck lid consider replacing the nose seal and case o-rings on the compressor; when the compressor case halves are separated you can inspect the wobble plate, pistons and bores for wear.

After the system is properly charged have then sniff the AC vents and condensation drain tube under the tub with an electronic leak detector; the evaporators for that year leak soon or later.

Do all of that and the AC system integrity will be good for many more years to come.

However, if you are aware that the stock system you have won't provide you with enough cold air, then you will want to consider some upgrades such as more condensers, better evaporator, maybe an additional vent. The upgrades should be done while replacing the hoses ....do it once, do it right.

Signed,
THE TROLL

The Mr. Ice Project

*** Or even less expensively, ~$200.00 range, convert to R-134a and use a trinary pressure switch with the extra element controlling 2 additional cooling fans for the rear lid condensor. Most modern day automotive A/C systems use a trinary pressure switch in very much this same manner.

Search: radiator cooling fans

LOL, nice.

Lol