Is it R12... or 134a...?
 

My sons 88 300TE...
Stickers say R12... no 134a conversion stickers.

Fittings look similar to airline fittings... ridges and an internal thread.
A friend of mine looked at it and says he thinks its 134a converted already...
Can anyone tell me?

12 would be a flare fitting w/shreader inside.

I would say that by the description of the fitting that it's 134a. But you can never be too sure that someone didn't just replace a leaky fitting with whatever they had at the time.

Threaded on the outside, right?:confused:

Correct ..a flare fitting.

For clarity R-12 fitting pictured below
http://www.aircondition.com/dsmobile...20fitting3.JPG

The photo of the Schraeder shown above is very much like a bicycle/motorcyle tube fitting. As stated - external thread.

Would not surprise me if someone converted with one of those $29.95 kits and didn't bother to install appropriate fittings, labels, etc.

I agree with your friend. With internal threads and ridges for a clip-on hose it sounds like 134a. Also, 134a fittings are a lot bigger in diameter than r12. The suggestion above that someone might have stuck on whatever they had at hand is a worthwhile caution, but it's easy to test.

Conversion kits have a 134a style fitting that screws onto the external threads on the r12 fitting. If you can start screwing this off, it's a pretty safe bet that it has been converted and it's 134a. If it's integrated with the hose the whole system has probably been replaced, and this is unlikely in the extreme, but makes it virtually certain that 134a is right. Either way, if it's got a 134a fitting, it's not a bad bet that the system has been converted.

I will post a picture later for clarification... Thanks everyone for your responses!
My son just passed his test....... :D :D :eek: and for some odd reason... could not wait around.... and took his Mercedes out for a spin.....:)

The fitting is integrated with the hose (which is pretty large diameter) if I remember... no adapters that I could see...

Congrats to your son...condolences to you...:eek:

The scariest moment in my life was when my oldest got into the car and, for the first time, drove off by herself.

I aged considerably at moment...now she feels confident enough to give ME driving tips....:eek:

Just replaced the rear rotors on my 16 yr old son's 420SEL because he didn't notice the parking brake was on. Broke the rotor in half.:eek:

it will get better....my son has had his 300e for a year and a half now....

he actually wanted to clean the engine tonight..... he has come a long way... he is 18.... i think he is starting to realize that he has a nice little ride...a lot is starting to kick in.... it better ...in three weeks he is off to college...

he's done things like brakes and various rubber elements... we still have an idler arm to do... i will help with that bad boy.... going to do the method where you cut off the bolt head, wiggle it out...and put the bolt in upside down

Ok.... maybe it is a adapter... what do you guys think?
http://img.photobucket.com/albums/v2...MercACfitE.jpg

So.....
If it was converted... what on earth do I do now....
Its not working... so I jumped the compressor by touching the pressure switch contacts.. and the clutch kicked in just fine.
What would you guys advise at this point?
Get it recharged with some 134 and some dye?
Vac and recharge?
Whats the best way forward?

Hopefully some of these guys will chime in that know more about A/C than me. That looks like 134a, and a new hose. But all the parts in the pic look new. Nice condition for an '88. In my opinion I would take it to a reputable A/C shop or good MB indy in your area. Let them evac., check the oil in the compressor, and refill with 134a. Shame though as I personally think R-12 is a better system, just too expensive anymore.

Jumping the pressure switch is a fairly safe way to check the function of the clutch on the compressor, but not a clear indicator of the functionality ( if that's a word ) of the complete system. Alot of variables to check, that's why I suggested a reputable MB independent service shop to look at it. Although that can be rather pricey.

Good luck.

Do I see an adapter fitted to a pre-existing schraeder valve or as previously suggested, a new hose altogether?