Ping: Jim Warman re: A/C integrity

The AC system on the automobile is actually a closed system.... leakage isn't supposed to occur but, of course, we are stuck with the shaft on the compressor poking out into the atmosphere (by the way, that's a pretty skookum seal in there). Add the numerous necessary joints, thermocycling and vibration and we have the opportunity for some sort of trouble.

Some systems seem to last years and years with no need for service and others seem prone to troubles - most fall somewhere in the middle. It's not considered 'normal' to have to add refrigerant (certainly adding on a regular basis is a red flag) though some systems do leech a little into the atmosphere over a long period of time.... I'm talking 5+ years between top offs.

Having said that, even on the 'leechers', it is expressly stated that I cannot add refrigerant without leak testing the system - if I ever got caught up in a government audit I would be looking at a rewarding career in the food, beverage and hospitality industry. Here in Alberta, intentionally releasing any refrigerant into the atmosphere would result in a $50,000 fine for me and an additional $500,000 fine for my employer. I don't know if this applies to DIYers. I am told that, in the states, a shop needs to be MACS certified to perform AC work though even R12 is freely available (here, only mining, logging and construction equipment is allowed to use R12 - automotive and over the road trucks can't add or refill R12 and must convert to R134a or use a so-called 'drop-in' refrigerant - this might leave you with an AC system that nobody will touch).

To cut to the chase...... no, they're not supposed to leak..... yes, they sometimes do leak..... AFAIK, no certified shop can legally add refrigerant without looking for the source of the leak. Private citizens can do as they please (apparently) but that is a matter of morals and responsibility..... not to mention local legislation.

At the risk of sounding like a 'watermelon' or tree-hugger...... for years, we slopped R12 around like water and now it has been linked to assorted concerns. My fear is that we will slop R134a around long enough to find out there's something the boffins hadn't counted on because of it.

HTH

BTW... thanx for the compliment.

Jim Warman snipped-for-privacy@telusplanet.net

intentionally

Down here in the states the only federal law is that you have to get certified to buy R-12, pretty easy test when I did it. But actually buying R-12 is another matter, as the price is absurd. It is usually cheaper to convert a system to R-134a and charge it than recharging it with R-12.

However, every state has its own laws regarding AC work. In some states it is practically unregulated, some require leak testing before filling, and have some pretty serious fines for not fixing a leaking AC system - even if it is R-134a.

Other than that, what he said....

Wulf

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ha, I second that one. My 95GT needed two new compressors under warranty. Once the warranty was over it kept on working for years until I sold it (and beyond that)

yeah, isn't the oil in the refrigerant very toxic ?

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** To cut to the chase...... no, they're not supposed to leak..... yes, they ** sometimes do leak..... AFAIK, no certified shop can legally add refrigerant ** without looking for the source of the leak. Private citizens can do as they ** please (apparently) but that is a matter of morals and responsibility..... ** not to mention local legislation.

I don't thing most DIY's around here care one way or the other. If I know I have a leak (somewhat evident - I have a UV lamp), I'm happy to replace whatever is defective before proceeding. Leaks don't ever get smaller, ya know?

Some compressors let a little more squeak out through the seals than others. I was under the impression that a tiny bit of leakage though the compressor was normal. IMO, a truly closed-system would involve encasing the compressor in a hermetically sealed container, as with industrial A/C systems. Apparently, the tech I spoke with was mistaken.

** At the risk of sounding like a 'watermelon' or tree-hugger...... for years, ** we slopped R12 around like water and now it has been linked to assorted ** concerns. My fear is that we will slop R134a around long enough to find out ** there's something the boffins hadn't counted on because of it.

R134a is frightening stuff. It is toxic as HELL. One good sized leak in the passenger compartment evaporator will kill everyone inside within 30 seconds. It's also extremely corrosive; PAG and ester have to be used to keep it from destroying everything in the A/C system. R-12 was not toxic at all to humans, and would only displace oxygen in a closed workspace. This stuff is much worse IMO, and I wouldn't mind seeing a better replacement sometime soon.

-JD

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** Running the ac about once a month (winter) will cycle the oil thru the ** ac system and will also help keep the seals good.

I always do this with Charlene for about 5 mins. once a week to make sure everything stays lubed inside. The only UV hit I get is around the compressor seal - everything else is tight as a drum. Since it's only 1-2 oz/yr., I figured it was normal. Any more than that, and I'll have to have it looked at by a professional.

-JD

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You do it yourself ? What do you use to top if off ? I wouldn't even know where to begin with it. My 95's ac kept running fine so I didn't bother.

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R-12 systems were expected to lose about 1/8 to 1/4 pound of freon per year thru seals and right thru the hoses themselves. Most of them held around 2 pounds of freon so you could go quite a few years before you lost enough that you noticed a change. Now days the federal pollution or whatever requirements for ozone depleting refrigerants require the loss to be less then that but I don't recall the exact figure. Plus the newest systems only use less then a pound of refrigerant. So they will lose less but as a percentage it can still be a significant amount over the course of a few years. One story I just read said that one of the Major Auto makers recently changed the amount of R134a they were putting in to the new cars by around an ounce or so because that tiny little change improved the cooling performance. The amount of charge is so critical it is going to be almost impossible to service new vehicles by the use of gauge readings

- it will take an evac and recharge using a VERY accurate scale.

Jim '88 LX 5.0 (now in car heaven) '89 LX 5.0 vert '99 GT 35th Anniversery Edition - Silver Mods to date - Relocated trunk release to drivers side, shortened throttle cable, PIAA Driving lights.

** You do it yourself ? What do you use to top if off ? I wouldn't even ** know where to begin with it. My 95's ac kept running fine so I didn't ** bother.

My '98 GT uses R-134a, and it charges through the suction port, up by the accumulator. Mine would probably work well for years and years, but I'm picky about A/C performance, and I prefer it work at its peak, so I check it yearly.

Unless you're very familiar with automotive A/C systems, it's probably best to let a professional handle it; I don't want to see anyone here get hurt fooling around with it.

-JD

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Anything with a name four feet long can't be good for us..... I never really have checked into the toxicity of 134 but I could see it displacing oxygen from an enclosed cabin (R12 would have the same effect in this kind of case). Occasionally, we will have and unexpected discharge of R134a in the shop.... it has a distinctive, though not strong, odour and no one appears to have suffered from it (R134a has a neat "burp" feature.... we can recover the product from a system and ten minutes later it will suddenly puke some more out).

One thing that we always hear is about any petroleum products carcinogenic nature.... I've spent nearly 40 years immersing various body parts in this crap and nothing has fallen off, yet (don't do this at home, kids). I have no doubts that this behaviour isn't real good, but I'm an old school guy and rubber gloves make your hands resemble bad feet.

Some of the so-called "drop in" R12 replacements contained a lot of butane and/or propane..... not the kind of stuff I'd like to see at 300psi in my car.... Perhaps they can one day perfect the transmogrifier and simply zap heat into cool. Until then, I feel it is important for each and everyone of us to handle harmful compounds properly and in a responsible manner. It is going to add to our expense but it will be cheaper to avoid making the mess than it will to clean the mess up later.

The only other solution is to ban these types of systems (tongue in cheek, here).... and that's easy for me to say since we have very few AC days up here... You folks in the south, however, will have to buy more deodorant. R134a was supposed to be a "safe" substitute for R12 until a replacement could be found.... Lord only knows what happened in the translation.

Jim Warman snipped-for-privacy@telusplanet.net

when you add refrigerant, do you use the refrigerant mixed with oil when you top it off or just refrigerant ?

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** when you add refrigerant, do you use the refrigerant mixed with oil ** when you top it off or just refrigerant ?

Only add oil if you have removed some from the system. Adding extra oil won't make it work any better, and may damage the compressor. As long as you don't have a leak in the system and it otherwise works fine, topping it off won't hurt anything. Use a high-side gauge to be sure you're not overcharging.

-JD

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hmm, okay. that makes sense but... If you need to top if off doesn't that mean some amount somehow disappeared form your system ? (small leak) ??

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** hmm, okay. that makes sense but... If you need to top if off doesn't ** that mean some amount somehow disappeared form your system ? (small ** leak) ??

Not always. If you can see oily spots on hoses or around the compressor, it's time to have repairs done. Normally, oil only gets added when repairs are done, and all of the old lubricant is expelled. It isn't an 'add a little once in a while' maintenance item.

-JD

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