DIY A/C work

[Drew99GT]

Well, my 94 Corolla hasn't been "putting out" lately. I topped it off with some High mileage refrigerent and some A/C booster stuff. The previous owner mentioned a top off a few years before I bought it. I took it in today and low and behold, it was so overfilled that the techs were in amazement that the whole system didn't explode

No more A/C work for me

Man I do some dumb things sometimes. I thought the compressor was shot for sure cause it was getting LOUD, I mean real loud. Now it's whisper queit and freezing. So, moral of the story, don't think those top off deals are your awnser. Seek the pros IMO for A/C work. Also, with those top offs, you'll add too much oil to the system. they also had to take off the reciever/drier and drain it along with cleaning out the expansion valve. Man I'm a dumb *** sometimes.

 

[benjamming]

Those A/C repair kits at Wal-Mart pretty bad. It's worse than not having anything at all. They don't have a pressure gauge for both sides!

 

[Chris142]

R12 was very forgiving. Give or take a few ounces and all is well.

With R134a a few ounces short will not allow oil to get to the compressor and overcharging a system will cause major highside pressures that can ruin the compressor, blow lines etc.

I really think that they should not sell 134a to the general public since it acts much differently that the R12 that people are used to.

 

[got boost?]

like anything else, without the right tools it's hard to do it right, a manifold/gauge set is what you needed.

 

[Crashbox]

I think I'll go environmentally-friendly and use direct-expansion R-717 in my vehicles. The high latent heat of R-717 enables me to use a very small compressor for the job... It's also "self-alarming"- you KNOW when there's a leak.

I suppose I could use R-744 also but that's not an environmentally-friendly refrigerant.

I already use R-718 in my radiators, mixed 50/50 with ethylene glycol...

Oh, yeah, about R-134- yes, it is considerably more charge-critical than R-12 was. Someone I know who is a refrigeration mechanic topped off my 134 system by measuring the duct temperature; when it hit about 47 degrees Fahrenheit he called it good. Works just fine too.

 

[Drew99GT]

I actually had one of those low side gauges you can buy, it kept reading low.

 

[andyd]

no direct experience, but Ive read that R134 needs about 3/4 the volume and pressure as R12.

 

[Crashbox]

I suppose I should expose the mysterious numbers (at least to some) in my earlier post-

R-717: Ammonia
R-744: Sulfur Dioxide
R-718: Water

It's real interesting to read through a list of various refrigerants that are/were used.

No, I wasn't serious about using ammonia in my vehicle even though it is arguably the most efficient refrigerant available.

EDIT: OOPS! R-744 is CO2, certainly evirofriendly!!!!! R-764 is SO2... The red on my face isn't sunburn!

[ July 23, 2005, 12:05 PM: Message edited by: Crashbox ]

 

[mechtech]

When hot, R134 has higher pressures than R12. It changes at a different rate.

 

[znamya]

Drew;

Did you tested the pressure when the A/C was on,you should have tested when A/C was on. I am very happy with Artic Freeze brand A/C charge kit. Try to buy that if you can

 

[Drew99GT]

Oh yea, 2,000 rpm, doors open with A/C on full blast.

 

[Chris142]

quote:

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Originally posted by andyd:
no direct experience, but Ive read that R134 needs about 3/4 the volume and pressure as R12.

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