Another A/C issue....

[TeKKnoTeKK]

I just charged my system yesterday with R134a, I must say I am a little disappointed with how cold it gets. Maybe it's just that it's so hot outside, but is there any way to get it colder?

[ACCORD EX]

what was in the system before ! R12 ??
MIKE

[TeKKnoTeKK]

I believe so....and yes I made sure to empy out the old stuff before putting in the new :p

[accordlx]

Vaccuuming the system down helps tremedously.

[Mike Murrell]

You mention changing to R-134a. What exactly did you do? If you just added R-134a, you've watsed your time.

As mentioned above, vacuuming the system is required. So is changing out the oil. Use Ester oil for a retro. PAG is good for native R-134a situations. Blowing out the compressor and condensor with air is also good. Expansion valves suited for R-134a are better than the orig. R-12 EV. R-134a pressures are different.

A/C efficiency is all about pressure. Different refrigerants have different pressures. These pressures affect temperature. In many cases, you'll never see R-134a cool as well unless a suitable condensor is also installed. R-134a pressure is increased in the high side of the system(condensor). The condensor converts pressurzied gas which is hot to cooler liquid. Higher pressure equates to higher temperature, thus, the condensor is having to work harder. The old R-12 condensor may not be up to the task.

Some people get away with plopping in one of the cheap-o retro kits sold at K-mart, Wal-Mart, etc.
Sometimes you get reasonably good performance. Many times you don't.

Long term, it's unlikely a cheap-o conversion kit will ever work for the long haul. If you're in northern Michigan or similar climate, the cheap-o fix may work for awhile. Note the word awhile. If you're in Phoenix, you already know it doesn't.

A/C repairs/upgrades require knowledge, training. Take the time to invest in training.

[ACCORD EX]

i was talkin today to a guy that charges AC with 134a and 12 and he said to me you can't charge a 12 system with 134a even if you suck everything out ! he said it will damage the compressor ! ?? :confused: :confused:

is this right ???

MIKE

[Mike Murrell]

R-134a pressures are higher. Reed valves in the compressor can be damaged using R-134a in an R-12 compressor.

[offthahook]

I thought the fittings would not allow you to put 134 in a 12 system. How are guys getting around this?? The valves/fittings on where you put the equip. to charge the system is what I mean...

[TeKKnoTeKK]

well when you buy the kit it comes with all the fittings for the conversion.

[‹^› ‹(•¿•)› ‹^›]

i HAVE BEEN WANTING TO CHARGE MY AC!!!
BUT LATELY A STRANGE SMELL HAS BEEN COMING OUT!!
EVEN WHEN THE AC IS OFF!! AND I DRIVE WITH THE VENTS OPEN!!
IT'S FUCKING HOT!! AND I REFUSE TO CLOSE THE VENTS!! BUT IT STINKS!!
IT'S A DAMP SMELL...ANY SUGGESTIONS!!:flash:

[TeKKnoTeKK]

maybe try some gas-x? :lol

[‹^› ‹(•¿•)› ‹^›]

FUNNY.....................
I WAS THINKING ARM & HAMMER:p

[njpeter]

some of the must-do's.....

1-you MUST change the dryer, the original one is for r-12 only, a r134 receiver is under $50. helps more then you think. Leave the original in there and it will spread goo thru the entire system ( there is a bag of dissectant which breaks when exposed to 134).

2-while it is great to pump the system down, I'll admit I have NOT done this--ever..the pump is not cheap to own. I can buy 4 used compresors for what the pump costs. they key is to keep the system open the minimum time possible. If you take a rock in the condensor or there is a large breech..you'll have to pump out..replace the dryer too. I'm fast with the saran wrap.

3-I've got ester oil in one accord, pag in the other, the accord compressor is the low point on the system, so the oil tends to stay where it belongs.

4-extra condesor cooling helps in really hot weather ( also during charging)..chargfe with a garden hose on the condensor. I've got a washer nozzel that sprays water on the condensor..a must for the sw(plain water only)

5-can't use sight glass to charge..134 expands more then 12..do not overchrage, the nd compressor seal will fail, keihns can't take the pressure of 134 at all. 80% charge is good. USE A GUAGE..a cheapie is under $25.

bad smells or "steam" is a sign of a low charge.


I've had most acceptable results with my conversions, and I fully expect to be replacing something every two years or so..but so far...so good..even with the used compressor and pag oil without a blow out on one, and esther on the other. AI don't run over 4k with the air on.

biggest tip..REPLACE THE DRYER!

regarding mold..that is nasty dangerous stuff in an a/c..I'd use lysol spray and baking sodea/water to clean it up I sprayed an entire can into the intake..granted the car smelled a little weird..but peace of mind knowing some of the stuff has been killed. extreme cases I've heard of had the entire evaporator clogged with a moldy mass of pine needles. if you don't see any water dripping on the passenger side nera the wheel whell look for the rubber drain hose..run a wire up there..don't drink that water!..don't run in recirc mode all the time as well..get some "fresh" air in there now and then.

stay cool!( I do)

one last thing, you cannot vent 12 or 134 to the air( that's a $25,000 fine if you are prosecuted for it-and people do)..if your system has gas in it you must have it "recovered" most shops won't touch you without big$$$ as there is no telling for sure what kind of gas is in the a/c, make a mistake and you've damaged or put int he repair shop a major expensive garage tool. You can buy recovery systems for under $500 on ebay..if you have a small group of folks who will use it, it won't sting so bad.

I've only had to repair systems with major component failures so far..so I haven't had to vent..it was really common in shops in the 80's when r12 went for a buck a can.

last thing(really)...wear goggles..big a/c accidents happen..$3.00 can save an eye (or two) Ha d a co worker take a valve core in the cheek when he pulled a guage the high side hose connector, there was a pop. big white cloud as the freon vented..he was bleeding badly from the cheek..lucky guy..me too..I was standing near the telephone

[DBMaster]

NJ Peter, you can RENT a very high quality vacuum pump at a local rental center, $11 - 4 hours. I have done this every time I replaced A/C components. To me it is not an option, but a MUST. Not only do you get all the moisture and air out of the system, it also helps you make sure you have a sealed system before you put in refrigerant.

Very good post, thanks!

[Lester Lugnut]

If you don't vacuum the system, you'll end up with a blend of the orig. R-12 oil and whatever you're using for the retro(PAG or ESTER).

You can buy a poor-mans vacuum pump for around $100 from various A/C parts providers on the WEB or take DBMasters advise and rent one next time. The $100 is easily reclaimed after you've done a few of these for $$$.

Long term, a blend of disparate oils can come back to haunt you.

Pretty fair post NJPeter.

[DBMaster]

Lester, I have been doing a lot of reading on this subject lately. If you are going to do the retrofit without changing compressors and completely flushing the system you should use Ester oil. PAG oils are used in factory R134a systems and do not combine well with remnants of mineral oil. Since it is pretty near impossible to remove all traces of old oil from an R12 system your best bet is to go with the ester oil (comes with the retrofit kits).

I would still avoid going with R134a, but that seems to be the lowest cost way of getting cool air thus the reason all the folks on this board are going that route.

[Lester Lugnut]

DBMASTER-Mike:

You're correct. Ester oil is the way to go if retrofitting from R-12 to R-134a. I too read this @ another A/C site. Think it was acsource.com. May be wrong about the URL.

What I'm hearing more and more of these days is the use of parallel-flow condensors.

The guys @ http://www.ackits.com can tell you about them.

Bottom line - R-134a high side pressures are higher than R-12. Higher pressure equates to higher temps. The old R-12 condensor being used cannot shed the additional heat.

[TeKKnoTeKK]

so essentially what you are saying is that you can use the condenser as is until it goes out, THEN you can buy a new one? lol

[Lester Lugnut]

You can use the original R-12 condensor if you like, but it may not function as well as one that's been designed for R-134a. In other words, you could spend alot of money anyway and possibly end up with a poorly performing system.

If money is tight you could keep what you have and live with whatever cooling the converted system provides. Wko knows? It might be acceptable. If you're in a reasonably mild climate like San Diego, Calif., you may be ok. If you're in Phoenix, Ariz., or some steam bath town like Houston, Tex. you might find yourself wishing for cooler vent temps.