weak a/c, bought a refill kit, should I do it? - PeachParts Mercedes-Benz Forum

yellowbenz · #1 07-13-2008, 02:12 AM

My 240D's a/c has been converted to R-134. It's weak so I thought about refilling. Bought a kit that has a low side pressure gauge and fill port. Now after reviewing some threads on this subject, I wonder if I should take it back and buy low side high side gauges from an autoparts store or maybe just take it to a shop. Anyone have an opinion about the various options?
Thanks

compress ignite · #2 07-13-2008, 03:35 AM

Chances are without a Parallel Flow Condenser the heat transfer co-efficient
will not keep you happy or cool.

Adding refrigerant without the proper gauges is playing roulette...
(and what's the old saying about the House always winning?)

Spend some time with your old friend the SEARCH function...

Personally,I can't stand trying to do something without knowing EXACTLY
what's needed and WHY.

280EZRider · #3 07-13-2008, 03:50 AM

I'm just curious: With the availability now of "Freeze 12," why is everyone doing the expensive change-over to R-134?

jkoebel · #4 07-13-2008, 04:02 AM

Buy the AutoZone manifold, with low and high side fittings for R134, and buy a better can tap adapter.

Run the A/C and read the pressures and figure out what to do based on that. This also has the plus of you can hook a can of anything up to it and add it at the same time you're measuring.

#5 07-13-2008, 04:16 AM

Freeze 12 is 134a.

Cervan · #6 07-13-2008, 06:39 AM

Quote:

Originally Posted by ForcedInduction

Freeze 12 is 134a.

Yep, blended refridgerant thats 70% 134a with a few other oddball freons. Low to none fractionation though.. remember, when your charging with a blended refridgerant you have to charge it as a liquid, or else you will only get r134a.

JimmyL · #7 07-13-2008, 10:51 AM

It is misleading really to say that Freeze12 is R134a. It has R134a blended with something else {R142b or something} but it does not have the same characteristics as R134a when working in the car.
It works better than R134a, although not as good as R12. But it seems closer to the function of R12 than it does to R134a......
And yes, get and use gauges no matter what you go with.

#8 07-13-2008, 11:10 AM

Its worth sticking with R-12.

Freeze12 is 80% R-134a and 20% R-152a, so it is R-134a. The fact still remains that the mineral oil used with R-12 does not mix well with R-134a and PAG oil should be used.

#9 07-13-2008, 01:33 PM

I agree, if you want decent AC stick to the correct coolant, R-12. Playing around with R-134a and the other stuff is a waste of time unless it never gets hot where you live/drive.

yellowbenz · #10 07-13-2008, 01:38 PM

It's already converted to R-134 so I was thinking about trying one of those kits that measures low side pressure and allows filling from that side.

Matt L · #11 07-13-2008, 02:14 PM

Take your second choice and return that kit in favor of a gauge set and manifold.

Get a 134a can tapper with 1/2" ACME threads, which is what it will have if it is a threaded fitting. (R12 uses 1/4" SAE, which is slightly smaller.) They're only slightly harder to find than the can tapper with the hose and fitting.

Be sure to purge the air out of the hoses before you connect them. You don't want to shoot air into the system.

JimmyL · #12 07-13-2008, 02:46 PM

Quote:

Originally Posted by yellowbenz

It's already converted to R-134 so I was thinking about trying one of those kits that measures low side pressure and allows filling from that side.

Folks aren't always addressing your specific situation. Sometimes there are points of view to get out there that take precedence......

I think we all know that R12 works best. But pay attention to the situation of the poster. Doesn't sound like they are gonna be rebuilding an AC system by themselves based on original post, so try and give the most helpful info for their situation.
Also, I have 3 W123's, all with working systems. R12 is better than Freeze12, but just a bit. Freeze12 is better than R134a, and by a wider margin than R12 vs Freeze12. So stating across the board that they are the same [Freeze12 vs R134a] is just not accurate info. Period! Doesn't cool the same, pressures aren't the same, and the contents are not identical.
Did I mention, WE ALL KNOW R12 WORKS BETTER THAN FREEZE12 OR R134A IN W123'

yellowbenz · #13 07-19-2008, 06:40 PM

So, I go out to refill my system. Was told by previous owner it had been converted. Hadn't really worried about that since I bought it; dealing with other issues and just really driving the car sans a/c. So, I start looking for the little blue and red ports and lo and behold they aren't there. Just two black ports. Look for the blue conversion sticker that I thought I'd seen before and it's not there. Just the red r-12 original sticker from the factory. Must have confused this with my late 190D which I KNOW was converted. So I guess I'm going to buy some R-12 off ebay and have a local shop fix it. Good news I guess.

Matt L · #14 07-19-2008, 06:55 PM

Find a shop with a refrigerant identifier, Yellow. They can tell you exactly what is in the system, and if it is contaminated. Expect to pay for this information, but you'll only pay for it once because from now on, you will know what is in there.

A shop without an identifier is unlikely to want to touch your car.

79Mercy · #15 07-19-2008, 07:54 PM

There is a product called HC-12, I goggled it and someone got vent temps of 22 degrees. It is compatable with R134a and R12a, you can use ether, PAG, or mineral oil. I think I might try it in my 280CE, R134 aint cutting it in FL where it is 90+ everyday.