328 Air-conditioning

Interesting theory. I did the sanden conversion 3 years ago using the adjustable bracket so as not to use the pulley tensioner. Measured up the belt with a piece of cloths line rope and went to my local NAPA dealer. Fitted up a gates belt and installed it. It has been running ever since and no problems. Belt is pretty tight and I see no signs of wear. The belt sits down in the crank pulley and also in the clutch pulley.

 

Here's one I picked up from Advance Autoparts I have not yet tried:

http://www.advanceautoparts.com/1/1/558043-expansion-valve-by-factory-air-part-38611.html#

Rated for:
1.5 Ton
R12 or R134a
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same here. Joe and his mech have upgraded 3-4 old 308's a/c systems and have not had an issue with the belts. Good to know though, I will look into it.

 

"
Here's one I picked up from Advance Autoparts "

Nice work - sadly they seem to be out of stock now...

Update - Just found it here - http://www.autopartswarehouse.com/details/QQMazdaQQGLCQQ4-SeasonsQQA-fs-C_Expansion_ValveQQ19811985QQFS38611.html

 

Look on the web at different auto AC places and you'll find a lot of replacements. Go to Vintage Air or some other sites. I found my stuff there , expansion valve and receiver drier.

 

Yes, there are a lot of alleged replacements that will bolt in but bolting in doesn't mean it's correct for the system. it needs to be the correct valve for the capacity and R12. That valve posted earlier does make sense - for a Mazda GLC of that era since it looks the same and was definitely used for R12.

The fact that testacajones pointed out that an original 328's ac cooled just fine makes it clear to me that the system as designed worked ok - subsequent "fixes" or changes plus normal wear apparently has made an OK system into a marginal (or worse) one.

So, as I said earlier, to me the most effective thing to do for a 328 is NOT to try and re-engineer the system with different condenser/evaporator etc, etc but to put it back to "original."

When I get to MD (and the car) late next month, that's my plan. I'll certainly advise everyone if it's successful or not.

 

FWIW - I decided to use R12 when I refurbish the system in a few weeks. I bought R12 (ebay) and will be flushing and then retrofitting the system with the original refrigerant, new exp valve, new dryer, new O-rings and possibly new hoses, depending on how the vacuum holds.

 

Did the a/c work today - Installed a new drier (Arizona Mobile air 37-13293), a new exp valve (4seasons 38611) and replaced all the O rings with new. Ran a vacuum to 29" and it held for an hour.

Then I recharged it with Duracool. I know I said I was going to use R12 but I had 3 cans of DC so I decided to try that and if it didn't work well, to evac again and use R12.

But it worked great and just as per DC's info, two cans was sufficient to fully charge the system and develop virtually ideal system pressures - 30PSI on the low side and around 150 on the high. The last time I charged with DC it took 5 cans and still could only get around 10PSI on the low side but over 200 on the high. Turned out that the problem, as I suspected, was the old (defective) expansion valve. NOTE that the "328 air conditioning article" (which is excellent in general) stated that he needed 5 cans of Duracool. If he had replaced the exp valve, he would have found (as I did) that 2 is correct and cools far better.

One minor problem occurred - after running at fast idle with the ac on full for about 10 minutes, the ac relay in the fuse panel quit and the system did too. I removed that relay and installed the one that was in the "Horn" spot (same rating) and it ran fine from then on. So I will need a new relay unless I don't use the horn!

It's not warm here today so I will wait till it's hot to make a real evaluation BUT the air coming out of the vents was extremely cold. I didn't put a thermometer on it - again, I'm going to wait for some hot weather for that. But the fact that the system pressures are as they should be and the proper amount of Duracool produced it tells me that the system is operating far better than it did before.

I BELIEVE it will cool the car just fine in hot weather but I'll delay any firm conclusion until it's actually put to the test.

 

Update - I did a condenser/evap vent temp check:

Ambient temp was 80F. Vent temp was 45. I added approximately 1/2 can of additional duracool and vent temp dropped to 38F. Adding additional DC raised the vent temp to 42 so I bled off a bit to get the temp back down to 38F. So it was able to drop ambient air by 42 degrees which is about as good as anyone can expect an ac system to perform. Pressures at 2000RPM was 28/130psi. The 328 vent temp was 8 degrees colder than my wife's MB could manage. Of course the MB delivers a lot more air volume.

So it will still take some really warm temps to tell whether the evaporator can actually supply a sufficient volume of the air to cool the car when temps are in the 90's.

 

I really need to finish my AC write up and post it....complete R&R of the system (similar to BlueMax as linked above).


Also, duracool is really not a good idea. It's flamable and AC shops will not work with it or on system with it installed. Please be sure that you attach a lable to your system to the next guy knows what is going on.

 

I too have been diligently working to get the AC in my 328 working fine. My problems started several years ago, when I ran the car on a nice April day with the AC on and parked it in the garage, I heard a seal on the compressor go. Bought a new compressor (rebuilt) but didn't install for a couple of months. When I went to install, I noticed the suction and discharge ports were reversed from the original. I tried to make it work, but the hoses do not have enough slack to connect, so I went back to the AC shop and they made a 6 inch rigid extension. Because of the movement of the engine/compressor, the extension lasted about a month.

On the latest round, I bought a new York-style compressor from Meridien in San Diego. Nice looking compressor, in original aluminum color, manufactured in China. I removed the 134a type oil and replaced with oil from ackits.com that already has the UV dye in it. Pulled a vacuum, verified it held for three hours and had it charged.

It has been about six weeks and yesterday, when it was 84 degrees ambient, I got 31 degrees out of the top center vent when running at freeway speeds for 10 minutes. I do notice the vent temp creeps up by about 10 degrees at long lights.

So for now, all is good, except if the car is parked in the sun and the black dash gets heat soaked to about 125 degrees--the A/C just never catches up.

Now the car is somewhat drivable on summer days early in the morning in Phoenix.

 

"It's flamable and AC shops will not work with it or on system with it installed. Please be sure that you attach a lable to your system to the next guy knows what is going on.


I agree with the label though no ac shop will ever see this car - it was poor ac shop work that "forced" me into learning about ac.

"I got 31 degrees out of the top center vent when running at freeway speeds for 10 minutes."

That's darned impressive! I haven't tried mine on the road yet. The 38F vent temp was sitting in the garage with the engine dialed up to 2kRPM.

 

I am currently in the process of replacing the A/C system in my 85 QV. I have installed a new Sanden SD compressor, $135 on ebay, converted the new compressor to the original Ferrari clutch and pulley, pulled new hoses, $120 at local parts/hose store, and changed to 4 Seasons/Parker filter/drier, $30 on Amazon. I need to change the TXV, flush the coils, and will use R12 for refrigerant. Mostly, remove and replace, but kind of tight working spaces. Note: use the correct torque specs for the hose fitting O-rings, they are not flare or ferrule fittings.

The latest issue, June '11, of Road and Track has an article about A/C starting on page 120 "Keeping Kewl." The last section of the article is titled "What's the deal with R-12 in older car." The article has some interesting information. Basically, R-134a will be a compromise in a R-12 system.

Also, I took the EPA 609 refrigerant test on the ASE website last week. "ASE Refrigerant Recovery and Recycling Review and Quiz." 30 multiple choice questions with the answers for the questions available on a drop down page of the test. You have to get 24 right to pass, but it is basically open book, answers provided, with no time limit. The ASE online test costs $15.00 and assuming you will pass it, you can buy R-12 refrigerant. You can print out a temporary certificate from the test results page.

DRG

 

Another update...

Today is was in the low 90s and quite humid so I figured it was a good day to die..er, I mean test the ac.

I started it up at around 2PM. The car had been in the marina parking lot all day so it was quite warm inside (ok, damn HOT!). I headed out and turned on the ac, keeping the windows open for a bit to exhaust some of the hot air. Then closed the windows and hit highway 50. After about 10 minutes at 50-60mph, the car was fairly comfortable but not nearly as cool as I'd like it to be. I had forgotten my thermometer but the air at the vent felt quite cold.

10 minutes later the car was actually "cool enough" BUT the sun had gone behind a cloud so I didn't have direct sun on the dash. And I still would have preferred it colder. Then I drove through the local area at around 30mph and the temp was still ok though I could tell the vent temp was higher than it was at 50mph.

At the moment I'd call the ac "somewhat effective" but it's got a way to go to be "good." I think that my 328's system is operating about as well as it can and I don't think there is any improvement to be had within the limits of the stock evaporator/blower. I might futz around a bit with varying the charge (Duracool) but I already believe I have the charge at the optimum level based on previous vent/condenser temp checks. So at the moment I'd say that the system works better than it ever has while I've owned it but it's not yet a "good" air conditioner.

 

Here in Florida, I drive about 90% of the time with the top off, so the A/C is useless then. But I do try and run it for about 15 minutes per drive just to feep everything loose and not have the seals dry up and start leaking. Also cycle the heating controls about every couple of months as well. Regular use of all switches, ect is part of good maintenance.

 

Mike,

Do you have a recommendation for a vacuum pump? Stupid question but can a vacuum be created with an air compressor?

Like every other 308/328 owner, I am learning everything I can about the AC system.

Does anyone have a lead on new or rebuilt Yorx compressor, the same model as what's in the 328?

And does anyone have experience fixing or rebuilding the original compressor?

-F

 

http://www.action-ac.com/AC-Part/20-10334.html

Paint it. Install it. Done. I tried a rebuild last year and it didn't hold. You need a two stage vacuum pump. RobinAir makes a good one. Go ahead and replace the expansion valve (Four Seasons 38611). I didn't and am now paying the price. The filter dryer can be obtain from Action AC as well. Can't remember the number though.

 

No stupid question, in fact, its a good question, furm. You can create a vac with a compressor using a venturi type device such as here:
http://webcache.googleusercontent.com/search?q=cache2_60M2QOQ0J:www.harborfreight.com/air-vacuum

Yes, its HF junk, but now you know its possible. Warning: this only goes up to about 29.0 or so " Hg. It states only 28.3, but I used it and got it to go higher (measured from my guages). Pros say gotta get the vac to 29.8 or 29.9 and there is a difference.

Best get a good vac pump like Futureman said. especially if youre spending for R12!

(I used the HF one on a Chrysler minivan a year ago- R134a. Pulled vac, charged, and 1 yr later no apparent problems.

 

Hi Furmano,

The A/C compressor at Action Air is great price - I got a new one last summer and paid $250. Make sure to get a new receiver/drier. They have them at ACKits.com (Arizona Mobile Air) for $11 (p/n 37-13293). The first one I bought came with a pressure switch but the second (bought as a spare) didn't, so you should probably order one just in case (p/n 29-30703) - about $20. The switch on the original receiver/drier has a female screw-on schraeder fitting that won't fit on the new receiver driers that take male screw-in switch fittings.

As for vacuum pumps unless you plan on doing this as a business, there are lots that will work. FJC ($), Mastercool ($), YellowJacket ($$$), JB, Robinair ($$) are all good brands. You don't really need anything larger than 1.5CFM, and a single-stage will work just as well for a small car system as the more expensive 2-stage pumps. Harbor Freight has some for around a C-note - check 'flea-bay' for bargains too. Just don't count on a venturi pump to get you lower than 29", and there is a BIG difference between 29" and 29+" of vacuum.

Buona fortuna,

Vincent

P.S. GTB's rule!

 

Thanks for doing so much research and sharing it. This is the stuff that really makes this hobby go. Awesome!

From my research: I was going to have a contractor put in home AC and that's when my education took it's next jump. At one point I called the mfg regarding the TXV, and I spoke with an engineer who went to some charts regarding line set, elevation diff between the evap & compressor etc, and tonnage to verify if I had the correct part. Anyway, I think (WILD GUESS) that the plaque on the compressor relates to R-12 max flow. From this, the BTU relationship might be had, and this again might convert to Tonnage ?-?-?

I'm basically too conservative to deviate from Ferrari's engineering. So I stay with R-12.

 

I have a Robinair vac pump and it works great.

Today I had the 328 out in mid-90s, high humidity and I now pronounce my 328 oem ac system (with Duracool but R12 should be the same) "acceptable." The car was sitting in the sun and it took maybe 15 minutes to get/keep the cabin comfortable to me and I tend to think I like a cooler interior than many folks. Their were no clouds and the sun was shining directly on the dash. What put the system into the acceptable level was removing probably one OZ refrigerant. I say "probably" 1 OZ because I don't have any way to accurately measure it.

I had been fooling around with the charge level and I believe I now have it right. This is a critical are for ac and, from what I have heard/read, it's the same as ignition timing settings...there is a standard "setting" (refrigerant charge in this case) but different cars "prefer" a different setting for best performance. So you have to be willing to futz with it a bit to get the best out of it. Obviously, on a higher capacity system, there is enough capacity to handle cooling the car even if the charge is not optimized.

As has been mentioned before, one of the little tips that helps is to have the dash vents pointed at the windshield, NOT at you/your passenger. On the 328 there is a little blue dot on each vent surround so you just point each vent at the dot and have it fully open.