Well my car is nearly drivable (except the tranny issue... different thread methinks).

I just recharged the a/c with 2 cans of Freeze 12 and I believe she's a leaky mess at the moment!! This morning she felt great; ice cold... this evening she leaves much to be desired.

My question for you AC guys is this; What's the best way to clean out and service the system, then recharge/add oil without taking out any components? Obviously I want to track down the leak and fix it first... But I think there's just loads of crap in the system that needs to be flushed. Now I know I can buy cans of AC flush for the job, but then what do I do about getting replacement oil back into the system? The compressor works very well (as far as I can tell anyway).

I know these questions may seem a bit elementary but I would really appreciate any help I can get.

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'90 300SE --- 173k miles --- (Odometer just stopped working!)

'85 Cali 300D --- 193500 miles --- (Second one) Sold Nov '10

'82 300TDT --- 236,xxx miles --- (My first one) Sold July '09

Well, getting it done properly will be now be a lot of money to do properly. You've contaminated the R-12 and even once you find a shop that will work on it they will charge a LOT to get it drained. After all they will have to replace all of their filters and dryers after vacuuming your system and then take the storage container to a disposal company. If you had stuck with the proper R-12 your solution could have been fairly cheap.

After you get your system drained then you need to pressurize it. The proper method is to use nitrogen but if you are going to replace the dryer then just compressed air will work. Use a spray bottle with a water/soap mixture and start spraying all of the system to look for air leaks. Just like you would for a tire leak.

After you've fixed the leaks then replace the dryer and switches. Get the system vacuumed and then fill with proper R-12. It is only around $90 to completely fill the system if you purchase the R-12 yourself.

Although now that I've reread your message you might want to do some tests first to determine if it actually leaked out. Is your compressor engaging?

BTW I just picked my '83 from a retrofit back to R-12. I'm down in the valley right now. 103 degrees F. outside and the cabin air is nice and cold!

So is there any need to remove the compressor to fill it with oil? The compressor is engaging fine at the moment....

So I would need to drain/flush the system, pressurize with compressed and replace the drier (with oil added to the new one, right?) and recharge? All this assuming I repair my leak first.... My biggest concern is ensuring the compressor has the proper amount of oil in it.... My logic keeps telling me that all the oil will come out of the compressor when I flush the system. Is this correct?

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'90 300SE --- 173k miles --- (Odometer just stopped working!)

'85 Cali 300D --- 193500 miles --- (Second one) Sold Nov '10

'82 300TDT --- 236,xxx miles --- (My first one) Sold July '09

regrettably the only way to know that there is the proper amount of oil in the compressor is to remove, drain, and refill it. if you had to recharge - some amount of oil came out with the refrigerant. So if you dont remove it youll just be guessing about how much to add, but I would add some. Too little no good - too much - no good. im not sure that your supposed to flush the compressor ?

Good Luck !

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1996 E300 110,000
1985 300TD 212,000
1980 300D 238,000

I think that some higher end machines can do an analysis on the oil level but I'm guessing that the older R-12 machines won't. To the best of my knowledge you'll need to drain and check. Hopefully someone with more experience in this particular matter will speak up.

I've only dealt personally with complete system installs with R-12. And only 3 of those.

Use the appropriate oil for your "New" refrigerant to cycle BY HAND the old oil
out of the Compressor!

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'84 300SD sold
124.128

Dude.... Such a bummer!

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'90 300SE --- 173k miles --- (Odometer just stopped working!)

'85 Cali 300D --- 193500 miles --- (Second one) Sold Nov '10

'82 300TDT --- 236,xxx miles --- (My first one) Sold July '09

NO! Don't change the oil to match the "new" refrigerant. That's one of the reasons for the mess he's in to begin with.

The PROPER fix here, AFTER finding and fixing the leak, is to break all connections and flush all components THOROUGHLY and then THOROUGHLY blow out all flushing agent. You can flush the compressor by hand with mineral oil or a synthetic substitute as the flushing agent. DON'T flush the compressor with solvent. Get as much oil out of the compressor as possible.

Distribute the correct amount of oil, 8 ounces I think, around the system as you put it back together. Use new o-rings everywhere and put in the filter drier last and then immediately evacuate the system then charge with R12.

It amazes me how many people absolutely INSIST on saving $30 or $40 on refrigerant by using something besides what belongs in the system and then cause themselves to spend hundreds to fix it. The same mathematics enters the picture when someone spends hundreds or even four figures to convert a system to a different refrigerant so that they can save that $30 or $40 on refrigerant.

I guess since I started learning my math in the fifties, a lot has changed when it comes to adding such things up.

Hahaha... crazy vintage math!!

Thanks buddy. That's very helpful. You've made the system repair seem intelligible and attainable.

Now, I just need to track down some R12. Anyone in Houston know where to get the hook-up?

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'90 300SE --- 173k miles --- (Odometer just stopped working!)

'85 Cali 300D --- 193500 miles --- (Second one) Sold Nov '10

'82 300TDT --- 236,xxx miles --- (My first one) Sold July '09

Every normal auto parts store has it...
but they usually keep it in the back..
AND it is really too expensive THERE...
find some on Ebay or something like that..
either way..
look up the EPA 609 or 608 ( forgot which ) test ONLINE... take it OPEN BOOK...
then you have your license to buy the R12 LEGIT....
about $20 the last time I looked....

One of the things you mentioned which was not sorted out is that your R4 compressor does not have an oil sump like something like a Sanden... so ALL the lube is being done by the mixing of the refrigerant and the oil as it goes around the system...
this is a different question than the deal about hand turning with the new correct matching lube ....

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1980 240d ,

chain elongation, cam marks reference:
http://www.peachparts.com/shopforum/diesel-discussion/10414-help-i-need-check-stretch.html

http://www.peachparts.com/shopforum/diesel-discussion/305365-9-degrees-chain-stretch.html

evap fin cleaning:

http://www.peachparts.com/shopforum/diesel-discussion/156207-photo-step-step-post-showing-w123-evaporator-removal-1983-240d-1982-300td.html?highlight=evaporator

A/C thread

http://www.peachparts.com/shopforum/diesel-discussion/297462-c-recommendations-mb-vehicles.html

Go to imaca.org, spend an hour or two at the most taking an online test for a $15 charge and you can then legally buy all the R12 you want. Buying it locally will be hit or miss, but ebay should turn some up.

I currently have about 30 or 40 pounds of the stuff, so I haven't been shopping for it lately. Due to decreasing demand the price seems to have come down.

Wow, Ebay has the stuff by the truckload! Awesome!

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'90 300SE --- 173k miles --- (Odometer just stopped working!)

'85 Cali 300D --- 193500 miles --- (Second one) Sold Nov '10

'82 300TDT --- 236,xxx miles --- (My first one) Sold July '09