A/C myths...question

[Q-less]

I was talking to a local A/C mechanic about the system. I bought a prelude and the lines in the system are empty, the a/c light comes on but you can tell the compressor doesn't kick on without looking under the hood because there is no engine surge noticeable in smaller engines. He told me that a compressor won't kick on since there is no freon in the system as a fault control over damaging the system. Is this true or just smoke up my arse? He is willing to pull a vacuum and put in the freon for a small fee, I'm gonna try to get some R12...yes I know about certification, but will try to get around that. He also will,for no charge,fill it up with a little leak detector for free before completely filling it up. I work with the guy and he does this on the side.

Anyway is this true? Is this based on most cars?

[Q-less]

BTW....surely we have some A/C specialists / technicians on board. I think it would be great to have an A/C MOD or a forum dedicated to such.Maybe NICO could combine some specialties like the "Car Audio, Entertainment & Security" and "Wheels, Tires, Brakes & Suspension" forums. I think it would be an asset....what could you pair with it?

Maybe "A/C, electrical & diagnostics"

[burijon]

Yes, this is true. I am no mechanic but I have read/heard that many times.

[Q-less]

I got excited when I heard this!! Hopefull, there is just a simple o-ring leak and no expensive compressor repair. I wonder how many people go in with empty lines and get suckered into a new compressor or extra labor. Great ammunition to bring along when going in for repairs!! Knowledge is Power!!

[Q45tech]

The mechanical part of AC has been available in cars since 1955 in volume.Hasn't changed much [R12 in use] in the 40 years [til 1994----R134a].......and then just the pressures, sizing, and oil types

People act like it is some mysterious rocket science. Books [simple and complex] have been available for all that time..........at least 50 years.

Whose fault is it if you don't understand the subject as well as the technican. With the INET and Google all excuses are worthless!

All compressors R12 and R134a [even R22 home ac/refrigerator] have high and low pressure protective cut off systems usually mounted on receiver driver.

If you walk in ignorant you may be treated as ignorant......depends on ethics and financial pressures of the moment.........if children are hungry ethics of goes out the window...........crack and ice tend to accelerate the process......loss of ethics.

[DAEDALUS]

Let's be fair about this. Folks come here seeking knowledge about their Infinitis. The fact that they're asking about a subsystem that's common is no reason to tell them to go to the internet. This is the internet! If that were the case we could get rid of 98% of all discussions...brakes have been around for 100 years, emissions systems for at least 30, fuel injection...several decades as well. We could keep it limited to ECU tables and call it a day.

[Jesda]

Check out a product called "Freeze 12"

[FarFetched]

What you would have to do is to recover (whatever is left in the system). Then evacuate (vacuum) for at least 15 min (takes out anything that's left after recovering proccess of freon). Then check if it holds vacuum at all. Shoud be steady at 30 inches if mercury/water there shouldn't be any (ANY!) drop/raise in vacuum! Very important ,if you don't know how long the system has been emty, to run A/C flush to clean out all that crap that has built up inside. Then you want to charge the system with proper amount R12 or R134a, add proper amount appropriate oil. Then check for proper operetion (with thermometer in the vent at 1500-2000RPM for at least 5 min)Long process short!Cheers!Why everyone cares about A/C system only when there is a need for it!I DON'T GET IT! KEEP IT IN TOP NOTCH ALL THE TIME NOT JUST DURING SUMMER TIME!

[Q-less]

I bought the Prelude with A/C not working though...informative post thanks

[FarFetched]

My last remarks/comments where not aimed at you at all. I said it in general!

[DominickJ30]

Weve had many discussions describing the process of A/C Recovery and Recharge. Just do a search.

[Q45tech]

Seems highly redundant and wasteful in the grossest sense to discuss how something works that is common to almost every 1955-1993 vehicle on the road.

Specific variations to Nissan would be a valid use of space.

As to Freeze 12 besides the other problems the Calsonic variable displacement compressor is internally set at 28 psi low and Freeze 12 needs 19-21 psi to duplicate the EXACT same cooling. That could result in an up to 8-10F warmer temperature [depends]. See belowhttp://www.autofrost.com/autodisc.pdf

"Beware of "quick 'n' easy" retrofits being hawked by all kinds of places. You might get a mechanic saying that conversion to 134a is just a matter of vacuuming the system and running-in a charge of 134a. RUN. Or, you might run into someone who wants to replace your R12 with "FR-12" or "Freeze-12" or "Frigc". These three (and several others) are simply 134a with an additive that makes it slightly less violently incompatible with 500sus mineral oil. RUN. You might also get someone who wants to put OZ-12 or HC-12 into the system. These two are blends of isobutane and isopropane. They work very well in R-12 systems, and have no oil incompatibility problems. BUT, they are flammable. To what degree this concerns you is an individual matter.

It's not as clear-cut as you might think, because *all* refrigerants are blended with oil in the actual system, and ALL refrigerants are violently flammable under catastrophic system breach conditions (refrigerant rushes out, creating aerosol mist of oil--BIG flameball whether it's R12, R134a, OZ-12, or Freeze 12, whatever). These hydrocarbon blends also are super cheap (about $1.25 for enough to charge a few systems). "

[Q45tech]

UP to board management what the lowest level of automotive education they will tolerate...........before the board fades into the past [downward death spiral] as so many have before. A fine line between the extremes.Numbers only mean something to advertisers and board owners.

I take the high road that it is mostly up to individual owner to educate themselves about the basics.............without spoon feeding students. But that's the entire US education system today so why should we be different and expect anything from our members...........so politically incorrect to not use the "special" word.

Maybe if we are extremely unluckily we will gather all the members from the other SPECIAL websites.........and discuss the pro and cons of spray painting our wheels black or 22" wheels in general.

[maxnix]

Thank you, St. Dennis, for showing us, the unknowing, the way to true automotive enlightenment.

I kid you not, I would be driving Hondas today at the same or greater cost and a hell of a lot less enjoyment if it wasn't for the knowledge you have shared with this board and its predecessors.

Function over fashion, always.