A/C brainstorming

[entirelyturbo]

Okay, got another question.

I think I'm finally going to get around to this sometime this summer. I'm just gonna put a new compressor in it, another new drier, new O-rings and call it a day.

Now, my question: I know the O-rings are shot from me letting the system sit unused for so long, so I don't have a problem replacing those. But, what about the hoses? Could they have decayed in a similar fashion from sitting unused for so long?

I just don't want to put the whole thing back together, then have the high-pressure hose burst open or something...

[Legacy777]

Are you putting a "NEW" compressor in, or a used one?

After all the BS I've dealt with, and where you live, I'd really recommend buying the new compressor from Subaru. I know it's not cheap....around $400 I think, but you shouldn't have issues with it in the long run.

Either way, you'll want to pull the condensor & evap and clean all the lines out with brake cleaner and compressed air.

You should be fine re-using the hoses you have.....hell, re-using the o-rings would "probably" be ok....but you may not want to chance it.

Also, if you decide to go with a new compressor, they come shipped with R12 oil in it. So you'll need to flush out the compressor as best you can if you decide to put r134a in.

I'f you put r134a in....I'd also recommend using PAG100 instead of esther oil.

[entirelyturbo]

I was gonna do a rebuilt compressor, but I can check my price on a brand-new one.

You used to recommend esther oil over PAG oil, what changed your mind?

[Legacy777]

I was gonna do a rebuilt compressor, but I can check my price on a brand-new one.

You used to recommend esther oil over PAG oil, what changed your mind?

2 knocking/dead compressors

and Vikash's recommendation that PAG lubricates better.

Who knows if the older compressors were already dieing....but per Vikash's recommendation I used PAG oil.

[vrg3]

Disclaimer: Even though I use my A/C pretty much every day of the year, I'm not in Florida or Texas.

PAG does lubricate better, but I've been doing fine with POE. One thing that helps is making sure to get the right viscosity. Calsonic compressors use the more common ISO 100, while at least some Zexel compressors use ISO 46.

I have also had great luck with the used compressor I put in a couple years ago. My opinion is that used is the way to go -- for the $400 that a new compressor costs, you could buy a half dozen used compressors plus all the equipment and supplies needed to replace the compressor yourself.

It's possible that sitting dry has damaged the o-rings and/or hoses, but like Josh says they're probably just fine if you do a good flushing. The hoses are unlikely to burst even if they're bad, though -- more likely you'd just experience a tiny amount of leakage. If you're worried about this, charge the system using refrigerant with UV dye in it so you can look for leaks visually when the system is running.

[Legacy777]

At nearly $100 a pop for compressors, and 2 compressors later.....the cost difference between new and use becomes closer.....plus if you consider your labor time to clean the damn system out every time & recharge it, not to mention the cost of a new receiver/drier, and refrigerent....it makes more sense to put a new one in.

Some may argue with that.....but my lack of frustration and time is more valuable.

[vrg3]

No arguments; just thought I'd express my personal preference on it. I understand yours.

[entirelyturbo]

Correct me if I'm wrong, but many shops have machines that not only flush the A/C system out, but put new oil in it when they charge it right?

If that's the case, I'm seriously thinking of just getting a new compressor, installing it, putting a new drier in, all new O-rings of course, R134a fittings, and letting a shop do the rest. I don't have any funky smells coming out of my vents (probably because I use the Vent function daily), so I don't think I'm gonna bother yanking the evap box out.

They're gonna hafta pull a vacuum on it anyway... might as well let them put the right oil in it and charge it. I've got a shop that I trust too, not some mom-and-pop place that will try to screw me over.

[vrg3]

It is possible to put oil in while charging. It actually isn't dependent on the machine but rather the can that you charge with. They make "oil charge" cans that include both oil and refrigerant. You shake the can vigorously to mix the two and then charge the system with it quickly.

I don't recommend doing it this way though. For one thing, not all the oil necessarily makes it in. Every time I've used an oil charge I've had some oil left in the can at the end. For another, I'd rather know that the compressor is well-lubricated before it turns at all.

If you evacuate the system properly, the vacuum does not remove oil from the system. And you can't flush the system with the compressor and receiver/dryer in the system anyway.

So -- flush the system, install the compressor and receiver/dryer with oil in each, and then evacuate and charge the system.

That's funny... I usually would trust a mom-and-pop place more than a chain.

[entirelyturbo]

Sounds fair enough... The only thing though, Josh said that the new compressor he bought had R12 oil in it. How would you recommend I get that oil out, as I'm aware that PAG oil isn't compatible with R12 oil?

[vrg3]

I didn't know new compressors came with mineral oil in them... But anyway:

Hold the compressor over a drain pan with the outlet pointed downward. Turn the compressor clutch by hand and you should see the oil drip out. You may have to swish it around inside the compressor and repeat the process a few times.

[Legacy777]

The new compressor that superceeded the calsonic for my car is still setup for R12, or at least I'm pretty damn sure because the fittings were still R12.

Because of that, I assumed the oil shipped in the compressor was mineral or some other R12 variant. I may have been wrong....but I didn't want to take a chance.

There is some a/c flush stuff you can use. It's a little on the messy side, but may be better for the compressor then brake cleaner.

[vrg3]

You make a good point about new compressors for old cars. I guess we don't know for sure what kind of oil is in there, so it makes good sense to get rid of it.

You're never supposed to flush a compressor with anything ever.

The A/C flush stuff I've used seemed to be pretty much the same thing as brake cleaner from what I could feel and smell. And since brake cleaner evaporates without leaving residue, and since you're pulling a vacuum on the system to make sure everything boilable boils, it seems pretty safe. The flush did come with a neat attachment (basically some hose and a rubber stopper with a hole in it) to make it easy to use though.

[Legacy777]

Sounds like you got a better flush setup then I did.

I ended up just using brake cleaner after I initially cleaned it with the solvent tank.

I think I may have ran some junk through the compressor....I don't recall exactly what I did....I may have not done much of anything. I know one of the spares I had I flushed with brake cleaner and chunks of metal came out.....so I wasn't using that one.

[vrg3]

The first time I did A/C repair, I used something like this:

http://www.graphics.cornell.edu/~v/pics ... _flush.gif

I subsequently used the tubing and stopper from that kit with a couple cans of Advance Auto Parts brand brake cleaner (which seems to be at a higher pressure than most other brands) on each of the other two cars that I retrofitted.

In all cases, I followed with many shots of pressurized air to get the flush and contaminants out.

[vrg3]

Okay, that link's broken. This is the picture:

http://www.autoklimatistiki.gr/pics/kay ... _flush.gif

[Legacy777]

That's pretty cool.

[jmaziarz]

7) Consider not retrofitting. R-12 has actually gotten fairly cheap lately. Depending on how much you buy at a time, the price can be as low as $20 for a charge! If you just buy enough for a single charge, it can still be as cheap as $50. Look on eBay.

R-12 is more efficient than R-134a, so you'll get colder air. It's easier on the compressor, so the compressor will last longer and will load the engine less. It carries mineral oil, which is very reliable and won't react badly with any of the stuff that's potentially gonna be in the system. It doesn't leak as easily. It's what your system was designed to use.

Why retrofit then when cans of R-12 are available still on Ebay?

I have a 93' Legacy that burned out a Calsonic compressor about a year ago. I purchased a used one (thanks blackbart!) an had it installed by a mechanic friend. After the install he said, "all you need to do is find someone to charge it with the old refrigerant and you are good to go." He didn't replace any other parts other than the compressor. It is a year later and the system has not been recharged. Can I just get some R-12 off of Ebay and charge the system or should I go through the process of retrofitting, i.e. will I need to do 90% of the work on the system anyway?

Thanks,
~Jer

[Legacy777]

If your compressor died, you at the very least need to replace the receiver drier. In addition, chances are the oil level in the system is not what it should be.

You could just pull a vacuum on it, and charge it up. It'd probably work, but chances are it will fail again. I've gone through 4 compressors before I finally just bought a new one.

I'd be cautious about the R12 you buy on ebay....and whether it's actually R12, or an R12 substitute.

The compressors on our cars suck.....they are notorious for killing themselves, and depending on how much you would use your AC, you can continue to spend money on it, or spend a larger amount up front. It's up to you.

[entirelyturbo]

This reminds me.

I've still got the brand-new OEM compressor kit sitting in my garage, all R12 stuff. New R12 compressor, new R12 high and low lines, etc. etc.

What I planned on doing was just making a brand-new R12 system out of it, since the compressor should already have R12 oil in it (you've said that before Josh), and the lines are made for R12 (I remember Vikash saying new R12 lines aren't good for carrying R134, only well-used R12 lines).

Now, do I have enough oil in my compressor for the whole A/C system? Or should I put an ounce of R12 oil in my new receiver drier too? Can I mix types/brands of R12 oil or do I have to use the same type?

With the exception of the O-rings and the actual R12 refrigerant, I have everything necessary to have a functioning A/C system. What I don't have is the time to do anything with it.

[evolutionmovement]

If you can get R12. Up here it's big $$ from any legitimate place if you can get it. I miss how well that stuff works compared to the new crap. My 260Z with its 20 yo system was better than most new cars and the Legacy could have made up for ozone depletion by getting it to Greenland and running the A/C with the doors open to reform the glaciers.

[Legacy777]

Michael,

Use a mineral oil with a 100 viscosity. As for the different kinds of oils....you should be ok, as long as it's the same viscosity.

If your compressor has been sitting for a while open to atmosphere, chances are the oil will probably have a bit of moisture in it.

[jmaziarz]

There is a good shop here that will charge you $87, then either charge the system with freon, or tell you where the leak is after the pressure test, you go fix it yourself, the come back for another pressure check and the freon at no additional cost. My ex-wife just fixed her Honda AC for a total of $200, including the charge and replacing the rock-holed condenser, with no experience whatsoever.

What is the name of this shop?

Thanks,
~Jer

[entirelyturbo]

By the way, we have a small chain down here called Ice Cold Auto Air, who is one of the more well-known A/C repair shops, and I inquired about R12.

They said it's still quite readily available, just expensive.

[jmaziarz]

I just bought a new receiver/dryer from all-foreign.com for my 93' Legacy for $25 (including shipping)! The price was way lower than many of the other online stores I looked at, now I think I know why. I don't have a picture (I'm at work) but the top of the unit has two rubber tabs that say "R134a" on them. Does that mean I can't use this unit in an R12 system or does it not matter?

Thanks,
~Jeremy