^Thank you Jimmy, this is what I was going for. And after seeing your picture of 42* out the vents I believe I can reach those temps with R12.

Im sorry but Colin can get better than 60F out the vents, prolly not with R134 though. I use enviro-safe freon in both of my cars. My W115 can put out 30 degrees at the center vents while moving, on a 80 degree day. However my W123 can't really get much colder than 45F out the center vents.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

' I used R-134a because I was worried it'd have a leak ' ~ that's why he goofed as one needs to re-open the system to change the typ of coolant , negating any leak test done with the R134a coolant .

You cannot have 30° out the AC vents as the evaporator core will ice up before that .

Each to their own I guess .

I'm still learning about this R134a stuff , it needs a slightly different operating pressure to reach maximum efficiency ~ the " Walking Tree Of Knowledge " @ the shop knows how to tweak an early , R-12 designed system to work as best it can with R134a but I still prefer R-12 in my own cars .

I hope all here know that it is *imperative* to run the AC for at least 5 minutes each week to maintain the system as the oil circulates within the coolant charge .

As always , my advice is free and worth almost 1/2 that .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Please stop insulting me and telling me that I goofed. Yes I was afraid I would discover some sort of leak, the system had nothing in it before I did all the work. Read this thread, I'm sure you would realize I had no idea what I was doing. I spent a lot of time and money in an effort to repair this system and was not sure if I had done it properly. I'm 19, I'm not a master mechanic and I'm doing the work on my own because I enjoy doing it.

I filled it with 134 because I had 3 cans laying around. I wasn't about to spend 100+ dollars on R12 only to find out that I did something wrong.

Yes I vacuumed the system, yes I replaced all the o-rings, and yes it held pressure, but no I was NOT confident in my work on the system at the time.

Give me a break, stop telling me that I "goofed" because I didn't. I merely was unsure of my work and didn't want to spend a ton of money on R12 if it didn't work when I had three free cans of 134 sitting in my garage. I had planned on using R12 if the system held up, and that's what I want to do.

Now all I wanted was an answer to my question, which is what I got. Please stop telling me that I goofed, I assure you I knew what I was doing when I put 134 in.

Colon -
First of all congrats on the efforts! You've stuck with it and probably have more experience in working on these "older" systems than many younger "master" mechanics that'll never see them due to the age of the cars. You've done the right thing.

And for many of us who are just starting out diagnosing our A/C systems, you've provided somewhat of a path to follow. Wish there was a definitive step by step to troubleshooting these systems...I've not been able to find it here, just cobbling together many threads to make sense of it all.

Let us all know how Norm likes the R-12 when you get to it.

WHOA ! ~

I didn't insult you .

You have done a masterful job here and I thought that was obvious .

I applaud your dedication to this job and following it through to the end and sharing your travails so others can learn too .

You done real good here , don't be so touchy .

I make mistakes too and I post 'em up so others don't follow in my footsteps .

This is called learning and I'm still learning after all these years .

I *think* that you , like I , have this older Mercedes as an actual car to be used and enjoyed , not as a hobby car ~ that's a good thing and you'll learn much when working on older machinery , especially when you encounter DPO & DPM bodge jobs .

Really , I didn't mean to insult you , you made a basic mistake and that's it . nothing to be upset about .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

FWIW ;

it is still out there , you just need to be *very* careful about mentioning it when you're searching for it .

It's a fairly serious crime to sell it so most folks who have it, won't admit it when anyone else is within earshot .

I paid $20 per shortie can last time .

I know a guy who has a 150 # cannister of it he says is for sale but he won't give me a price ~ this is frustrating to the extreme .

Once in a while I see the shortie cans at yard sales for $1.00 each....

You've gotta beat the bushes when you want a thing .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

What type of oil did you use? If it was PAG you can blow out most of it, leaving the drier alone, then add ester oil. Ester is compatible with mineral, PAG, & parafin and is also compatible with both R12 & R134a. If you used ester oil you're good to go, just evac & recharge with R12. Mineral oil is only compatible with R12 & hopefully you didn't use it with the R134a, unless you only used the ac for a short time to test it, then no harm will be done (they don't mix causing a lack of lubrication if run too long). If you did use mineral oil, just evac & recharge with R12.
When you remove the R134a, do it slowly. If it comes out too fast it causes turbulence in the drier which can rupture the desiccant bag. If that happens, it will clog up the expansion valve next time you use the a/c.

__________________
82 300SD 202K
82 300SD 233K
83 300TD 340K
82 300TD 98k euro (parts on the hoof)
85 300TD 282K
83 300TD 197K

never gets old...

__________________
1985 500SL Euro w/ AMG bits 130k
1984 300SD Turbodiesel 192k
1980 240D Stick China 188k
2001 CLK55 AMG 101k
2007 S600 Biturbo 149k Overheated Project, IT'S ALIVE!!!

R12 is going to help but you're never going to be completely comfortable during a Florida summer. When it got over 90 degrees around here I wouldn't drive R12 equipped Ol' Turbo because the AC couldn't keep up. Even the AC master Jimmy during the hot Texas summer months retreats to his Ford truck.

My wagon came from Sedona Arizona, and had a very dark tint on all the rear windows, and a slight tint on the front two. With a reflective screen in the windshield the car barely heats up above outside temperature. All the windows on wagons makes it a rolling greenhouse, which the AC even with R12 will never successfully overcome. This was even an issue with my mighty 2004 E500 wagon. The cabin would get so hot even with excellent ac and ventilated seats it took a very long time for the cabin to reach a comfortable temperature.

__________________
1985 500SL Euro w/ AMG bits 130k
1984 300SD Turbodiesel 192k
1980 240D Stick China 188k
2001 CLK55 AMG 101k
2007 S600 Biturbo 149k Overheated Project, IT'S ALIVE!!!

I was getting low 40 degrees out of the vents using r134 last summer. Its definitely possible.

__________________
1982 240 D, 308,000 - 321,127 miles (sold)
1982 300 TD,166,500 - 226,000 miles
1998 E 320, 120,000 - 144,000 miles
2005 C 230 K, 26,000 - 77,000 miles (sold)

It's alright, don't worry about it. It was just a little frustrating to see someone say that I messed up after all the time I put in to it. I'm over it though, no harm no foul.

And really, thank you for the help you've given me in this thread.

I'm fairly positive that I used ester oil, because I remember seeing PAG oil and not wanting to use it. Also I believe that the bottle said "for R12 and R134 systems". I have the bottle sitting in my garage somewhere, so I'll go verify that. It's good to know that I could just evac and then recharge the system with R12 with that type of oil.

I have wondered if tinting my windows would help, but never really had the ambition to do it. I know that it would be a ton of fun getting those rear cabin windows tinted! I might actually try this should I not be comfortable with the R12, I'm sure Norm wouldn't mind.

I took this picture today outside temp was about 82 degrees, car was moving.

__________________
1985 300TD Turbo Euro-wagon
1979 280CE 225,200 miles
1985 300D Turbo 264,000 miles
1976 240D 190,000 miles
1979 300TD 220,000

GONE but not forgotten
1976 300D 195,300 miles
1983 300D Turbo 175,000 miles

http://i42.photobucket.com/albums/e3...e485-1-2-1.jpg

I went through this some years back and it turns out the the best UV blocking
isn't the dark tint ~ research the 3M tint films and you'll find a very good UV (heat) blocking film that's not terribly dark so not only can you see out , the cops won't be hassling you either .

Most folks automatically buy the darkest & cheapest film so they look cool (or stupid) then think that tinting doesn't help so much when it does , if you do it right .

I'm flabbergasted to see that 30° C dash vent temp . very cool indeed .

I have a bottle of Ester AC oil , I *think* it says R12 & R-134a compatible .

It's a PIA to keep track of how much total oil you put in , too much and the system loses efficiency , too little and the weeny Delco R-4 compressor grenades on a hot day...

As long as it's cool(ish) and dry in the car , I'm happy .

__________________
-Nate
1982 240D 408,XXX miles
Ignorance is the mother of suspicion and fear is the father

I did then what I knew how to do ~ now that I know better I do better

Time to revive this thread.

I placed an order for a brand new compressor/drier/expansion valve. I'm going to be using R12 this time should I be able to find it. Tinting is also in the works.

Let the battle for cold air continue!