I'm interested in getting my A/C fixed. First I want to know what type of system my car has in it now. Is there an easy way to determine if my car is setup for r-12 vs. r134a.

Thanks

__________________
'85 300td Frybrid WVO Kit

The ports will tell you if it has been retrofitted - schrader valve means original R12 still in place. Slip-tip means it has been retrofitted, probably to R134a, but could be a blend or some alternative.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Mine had been converted in 1992 by a Mercedes dealer to R134a according to the maintenace records. It looks like it was a free service back then. All the maintenance records show that it was refilled with 134a since then but get this: They never changed to the 134a fittings. It still has the R12 screw on fittings. Go figure....

__________________
1991 300D 2.5 Turbo (185000 miles)
2002 BMW 330 cic (65000 miles)
2000 Vulcan Classic 1500 (47000 miles)

Thanks for the replies. Could you please clarify where I should be looking for the schrader valve? Also, if the car has been retorifitted for 134a, is it still possible to fill with r-12 (assuming I can find a shop that has it available). From the posts I've read, 134a doesn't seem to do a great job cooling.

thanks again

__________________
'85 300td Frybrid WVO Kit

The ports are under the plastic caps. The most accessible one is on the big thick hose that crosses right in front of your valve cover. Standing in front of the car, the port is slightly to the left.

The only safe way to retrofit back to R12 is to open the system up, clean it entirely out with solvent, and replace the drier and compressor (and probably the expansion valve). The oil used for R134a is incompatible with R12.

Good luck getting a shop to do that. Best to do it yourself after you get EPA certified. (Do a search and you will find loads of info on fixing your AC and getting R12 legally).

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Yes it is still possible. I have r134a ports and r12 in the system. My gauges accept r134a fittings. So when I converted my sysem back to r12 I left the r134a fittings on. Although most shops will probably want to change the fittings back. Most of the time the r134a fittings will just unscrew from the old r12 fittings. In my case I had a custom hose made with a new r134a fitting so I couldn't do that.

For what its worth, I had negligable difference between r12 and r134a. Others speak differently, but in my experience they both cooled the same in my system.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

That is not necessarily true. Some oils work with both.
http://www.ackits.com/c/Compressoroils/Auto+AC+Compressor+Oils.html
BVA 100 from ackits works with both.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

True, but if you don't even know what kind of refrigerant is in the system, it's probably best to assume the oil is incompatible.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT

Yes, most definitely. Flush with the oil you are going to use afterwards.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

If you don't INTIMATELY know the refrigeration history of the car, the ONLY way to learn what refrigerant is present is with a Refrigerant Identifier. If you're not quick to turn loose of $800 or $1,000 to buy one, your local auto a/c shop will have one.

The other positive way to know what refrigerant is present is to recover the refrigerant and recharge with KNOWN refrigerant. Since it is illegal to recover refrigerant into a container that does not contain like refrigerant, what else are you to do besides use a Refrigerant Identifier?

That is true but he may not even have any refrigerant in his system at this point. If it had a leak it is long gone by now.

If it does contain refrigerant he could put it into an empty container to later be identified. I don't believe that is illegal but Larry you would know better than myself on that.

__________________
2009 ML320 Bluetec
1985 300CD
1981 300TD

Past Mercedes
1979 300TD
1982 300TD
2000 E320 4Matic Wagon
1998 E430
1984 300SD
1980 300SD

How can you put it in an empty container? You would need vacuum on that said container I would think. If the system is empty, then it is the best time to replace the compressor, drier, and expansion valve, then do a total flush and refill with R-12, if he can.

__________________
RRGrassi


70's Southern Pacific #5608 Fairmont A-4 MOW car

13 VW JSW 2.0 TDI 193K, Tuned with DPF and EGR Delete.

91 W124 300D Turbo replaced, Pressure W/G actuator installed. 210K

90 Dodge D250 5.9 Cummins/5 speed. 400K

I have a similar problem....

A couple of weeks ago I aquired a 300D W123 with A/C--Pretty rare in the UK...

It has the R12 fittings so I assume R12 fitted, but has very little pressure...

As I'm in the UK, we dont really Need A/C much, so I don't really want to spend a mint on getting it working...

R12 doesn't seem to be available anymore,--Is there a safe equivalent I can use to top-up/re-fill system without replacing all the parts in the A/C system...?

__________________
http://i190.photobucket.com/albums/z...0TDnoplate.jpg

Alastair AKA H.C.II South Wales, U.K. based member

W123, 1985 300TD Wagon, 256K,
-Most recent M.B. purchase, Cost-a-plenty, Gulps BioDiesel extravagantly, and I love it like an old dog.

W114, 1975 280E Custard Yellow,
-Great above decks needs chassis welding--Really will do it this year....

Vacuum the container (and lines) to empty it of all air (unless the air is already displaced by refrigerant vapor). Place the container in a bucket containing dry ice. This will remove the refrigerant. Per EPA specifications, you need to pull a 4" Hg vacuum to consider the refrigerant reclaimed.

@Matt


I have seen some mention on here of using a salvaged refrigerator compressor to reclaim refrigerant. I don't have one of those, but I do have a vacuum pump. Can I use this same vacuum pump (oil type) to reclaim refrigerant from the system? The pump has a second fitting on it, but I am not sure if that is where the purged air/gas is evacuated.

__________________

Current Mercedes
1979 maple yellow 240D 4-speed

Gone and fondly remembered:
1980 orient red 240D 4-speed

Gone and NOT fondly remembered:
1982 Chna Blue 300TD

Other car in the stable:
2013 VW Jetta Sportwagen TDI / 6-speed MT