any car air-conditioning experts?

[Dan Schultz]

Joe... it's Father's Day. Shouldn't you be beating.... er, I mean spending time with your kids?

[Todd S. Malicoate]

Your 2000 Prizm uses a Harrison V5 compressor. Harrison compressors take PAG-150 oil or you can opt for the "universal" Ester 100. The proper procedure is to drain the old compressor and add that same amount to the new one, but 4 oz. is generally "about right." Drip about 3 oz. into the accumulator inlet as well before you install it. Remember to keep the drier "closed" to the outside air as much as possible to prevent the ambient air from ruining the dessicant inside. Make the installation of the new drier the last thing you do before charging the re-sealed system.

[Rick Denney]

Joe,

There is probably oil accumulated in other parts of the system. The fact that none was in the compressor is not panic-scary. But you do need to add oil.

If the system has PAG oil in it already, use PAG. Ester oil's compatibility is more with R-134 than with PAG oils in the system. R-134 is incompatible with the mineral oils used with R-12, and that's why they switched to PAG in the first place. Ester oil is used in R-12 systems that are being converted to R-134, because it will work with all types of refrigerant. Ester oil will work, but you should really use PAG since that's what is already in it.

Make sure you pull a hard vacuum on the system after connecting all the hoses but before before charging it. You really MUST get every bit of moisture out of the system before putting in the refrigerant, or that dryer won't last ten minutes and you'll get ice crystals in the evaporator.

I found a $75 displacement vacuum pump at Harbor Freight that works perfectly for pulling a hard vacuum. You need a pump that will pull 29.9something inches of mercury vacuum, not the venturi vacuums that just won't pull a hard enough vacuum. Stay away from those cheaper vacuum pumps that work using an air compressor. Just hook it up to the center hose on a set of gauges and let it run for an hour or two with the valves open. Then, turn off the pump, close the valves, and let the system sit. Then open the valves and check that the vacuum is still being held--that's a test against leaks. With a hard vacuum, you'll be able to get enough refrigerant into the system so that the compressor will run when you start the engine.

You can also convert the system to HC-12a, which is a hydrocarbon refrigerant (aka, highly refined propane). It is a bigger molecule, which means it's less likely to leak, and runs at a lower head pressure, which helps the compressor last longer. But you'll have to mailorder the cans. It is compatible with all lubricants, and is not nearly as fussy at R-134. It also makes cold more effciently. And it's cheaper than R134.

I hope you have better luck with the rebuilders than I've had. I've had trouble getting a Four Seasons remanufactured Harrison-type compressor that will really last. My one vehicle that uses that A6 compressor is about to get modified to a Sanden compressor when this latest ramanned compressor dies.

Rick "moisture kills refrigeration" Denney

[The Big Ben]

1. Move to Washington State- wet side.

2. Roll down window.

3. Done

[Todd S. Malicoate]

Thanks Rick.
AutoZone (hate/hate relationship - probably part of the reason - indirectly - I left Memphis after 50 years) has a (nice) program where they loan out vacuum pumps (no time limit). You put the value of the (used, of course) pump on your c.c., and when you're done with it and return it, they give you a full refund. That pump is already here with me. I plan to pull a vacuum for a good, extended amount of time, as I was already strongly told to do this...and yes, my choice was between Four Seasons (Chinese crap), a "real" one (around $400 - OUCH!), or a rebuilt "factory" one. The seller on eBay has "compressor" as part of their name, and has 99.8% positive feedback (VERY high, PARTICULARLY considering it's " car air conditioner compressors"). I figured a rebuilt Nippon (rebuilt by someone who apparently offers good service, as my original Nippon lasted 13 years) would be better than a ("pretend compressor" Four Seasons). I appreciate the instructions !

bloke "simultaneously doing a rotor/pads brake job, since the front brakes shimmy just a bit, and the passenger front wheel has to come off to get to the compressor anyway"

Four Seasons is not "Chinese crap." That brand, Murray, and Everco are all made at a factory in Lewisville, TX. Also, what do you mean by "Nippon"? Your Prizm shows a Harrison V5 and not a Nippondenso compressor. If it is a Nippondenso, those take PAG-46. Kind of a big difference.

Rick, I'm amazed you're recommending Enviro-Safe ES12a (or HC-12a as you called it) to someone, particularly to someone who already has a working R-134a system that (presumably) cools just fine. If you have to add pine scent to mask the offensive propane odor of the product that should send off a warning flare. The volatility of propane at pressures around 400psi should be another.

HC-12a is provisionally against federal law and against many state laws as a refrigerant in moving vehicles (see here). Buy at your own risk. It's also not cheaper than R-134a in many areas. The store I work in sells 12oz R-134a cans for $6.99 ($6.20/can by the case). ES-12a comes in 6oz cans and costs nearly the same for half the product. Yeah, I know, they say it only takes 1/3 the product to cool "just as well." I call BS on that claim.

[Rick Denney]

Rick, I'm amazed you're recommending Enviro-Safe ES12a (or HC-12a as you called it) to someone, particularly to someone who already has a working R-134a system that (presumably) cools just fine. If you have to add pine scent to mask the offensive propane odor of the product that should send off a warning flare. The volatility of propane at pressures around 400psi should be another.

HC-12a is provisionally against federal law and against many state laws as a refrigerant in moving vehicles (see here). Buy at your own risk. It's also not cheaper than R-134a in many areas. The store I work in sells 12oz R-134a cans for $6.99 ($6.20/can by the case). ES-12a comes in 6oz cans and costs nearly the same for half the product. Yeah, I know, they say it only takes 1/3 the product to cool "just as well." I call BS on that claim.

I've never heard of "Enviro-Safe ES-12" and the can of HC12a I'm looking at doesn't say anything like that.

It is not against Tennessee law to use HC12a as a refrigerant in automobiles, nor is it against Federal law. It is against Federal law to use it as a replacement for R12 and other ozone-depleting refrigerants, which R134 is not. Bloke was talking about an R134 system, and that is a legal conversion.

Of the 30 million-plus vehicle AC systems that use HC refrigerants, there has never been a report of a car fire caused by the refrigerant, let alone at a rate higher than for cars that use R134. And 134 is flammable, too, when mixed with PAG vapor. Also, when it burns, it produces Phosgene gas. Propane is far less dense than 134, and tends to blow through a leak into air faster than its flame front, which means it usually blows itself out. If it leaks into the passenger compartment, you'll smell the oil of mercaptan that is used as an odorant, long before it reaches a concentration required to support combustion. Open a window if that happens.

While this won't impress Bloke, most environmental organization support the use of HC refrigerants, because they are the least damaging to the atmosphere when released.

HC12a is also as effective as R12, and much more effective than R134. It is a big molecule that doesn't leak as easily, and it's compatible with any oil. And that effectiveness comes at about half the normal head pressure. My large system, which I converted to 134 and then installed HC12a, uses perhaps 20 ounces total, and runs at about 170 psi on the high side and 23 psi on the low side at 1500 RPMs of the engine.

Call BS if you want, but unlike you, I've actually used it.

Rick "who wouldn't have suggested it if it wasn't legal and a good idea in Bloke's situation" Denney

[Todd S. Malicoate]

I've never heard of "Enviro-Safe ES-12" and the can of HC12a I'm looking at doesn't say anything like that.

It's just one company marketing HC-12a, and they put a "fresh pine scent" into their product to cover the mercaptan in the propane. That strikes me as incredibly irresponsible considering the whole point of the mercaptan is to warn people that they are inhaling propane! If other marketers of HC-12a don't do this, good for them, but Enviro-Safe is the brand that most folks around here get...it's made by the fine folks who brought you Freeze12 (a product that was about 95% R-134a but engineering to carry the R-12 mineral oil).

It is not against Tennessee law to use HC12a as a refrigerant in automobiles, nor is it against Federal law. It is against Federal law to use it as a replacement for R12 and other ozone-depleting refrigerants, which R134 is not. Bloke was talking about an R134 system, and that is a legal conversion.

Federal law is sketchy, since the EPA still hasn't made a ruling about the use of the "new" HC-12a reformulation. They've dragged their heels for over 3 years now on this, but they still haven't issued a ruling. So yes, it is still legal to use HC-12a in vehicles that didn't originally use R-12 unless you live in Arkansas, Arizona, Connecticut, Florida, Idaho, Iowa, Indiana, Kansas, Louisiana, Maryland, North Dakota, Oklahoma, Texas, Utah, Virginia, Washington, Wisconsin, or the District of Columbia. Those states all prohibit the use of flammable refrigerants in mobile A/C systems.

Of the 30 million-plus vehicle AC systems that use HC refrigerants, there has never been a report of a car fire caused by the refrigerant, let alone at a rate higher than for cars that use R134. And 134 is flammable, too, when mixed with PAG vapor. Also, when it burns, it produces Phosgene gas. Propane is far less dense than 134, and tends to blow through a leak into air faster than its flame front, which means it usually blows itself out. If it leaks into the passenger compartment, you'll smell the oil of mercaptan that is used as an odorant, long before it reaches a concentration required to support combustion. Open a window if that happens.

Agreed that the risk of an explosion due to refrigerant is minimal. The biggest risk would be a buildup of fumes in the cab from an evaporator leak which Enviro-Safe chooses to mask. My beef isn't with HC-12a in general but of that particular practice. It's indefensible.

While this won't impress Bloke, most environmental organization support the use of HC refrigerants, because they are the least damaging to the atmosphere when released.

No disagreement there. While R134a doesn't deplete ozone it is a greenhouse gas that certainly doesn't help the environment when released.

HC12a is also as effective as R12, and much more effective than R134. It is a big molecule that doesn't leak as easily, and it's compatible with any oil. And that effectiveness comes at about half the normal head pressure. My large system, which I converted to 134 and then installed HC12a, uses perhaps 20 ounces total, and runs at about 170 psi on the high side and 23 psi on the low side at 1500 RPMs of the engine.

Call BS if you want, but unlike you, I've actually used it.

I don't use it in my personal vehicle, but I've installed it and seen similar results. My experience is that it takes about 75% the amount to achieve the same duct temperatures as R134a with, granted, a correspondingly lower head pressure. I take issue with advertisements that claim it works just as well as R134a with 1/3 the volume. That's pure BS.

Todd "not meaning to start a heated argument with Rick, but I really hate that Enviro-Safe stuff" S. Malicoate

[Rick Denney]

It's just one company marketing HC-12a, and they put a "fresh pine scent" into their product to cover the mercaptan in the propane.

Freeze-12 was always a different product. HC-12a and Duracool are both made by Oz or some such.

Of course, hydrocarbon refrigerant is not patented like R134, so anyone can make it.

Here's a supplier for HC-12a in Tennessee. I bought from them when they were still Fox Tool and Supply. There is certainly no pine scent anywhere in that stuff. I'm not sure it would be possible for three cans of this stuff to reach a 2 or 3% concentration if it all leaked into a decent-size car. But that's why it has an odorant, which R134 doesn't have, even though it's not exactly healthy to breathe it, either.

http://bennettsupply.net/cart/parts.htm

Rick "thinking R134 ought to be illegal in states that outlaw 'flammable' refrigerants" Denney