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  #1  
Old 06-30-2004, 11:00 AM
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What is this part? Air conditioning?

I feel kind of dumb asking this question, but I have absolutely no knowledge about A/C systems... I tried looking in the service manual I have, but it didn't help me out.

I have discovered some sort of bright yellow oily fluid leaking out of what I suspect to be part of the air conditioning system... see attached photos. This is on a 1984 190D-2.2.

Does anyone know what this part is, and what is leaking out of it? Should it be fixed ASAP, or can I leave it? Should I avoid using the A/C until I get it fixed?
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What is this part?  Air conditioning?-ac_leak_1.jpg  
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  #2  
Old 06-30-2004, 11:01 AM
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Photo #2

A close-up photo of the leaking part...
Attached Thumbnails
What is this part?  Air conditioning?-ac_leak_2.jpg  
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1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD
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  #3  
Old 06-30-2004, 12:01 PM
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That's an A/C line and the cap covers the schroeder (sp) valve where the pressures are checked and the refrigerant is serviced.

What is leaking is compressor oil. Is it an on-going leak, or could you perhaps clean it and it stay dry?

If it is truly leaking you will need to have a shop drain the refrigerant, replace the stem in the valve and re-charge the A/C.

Most likely, the oil was just left as excess that spurted out when someone last tested, or serviced the refrigerant charge. Clean it off and check back later... It is ok to remove the plastic cap. Nothing should come out. If it hisses, or bubbles when you remove the cap, put it back right away and have the valve stem replaced...

Good luck! Hopefully some mechanic just left a mess...
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  #4  
Old 06-30-2004, 12:06 PM
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Its the dye

You system must haev been serviced before and they inject dye in it to see where the leaks are. Looks to me that its possible that nut is not tight. Tighten the nut and wipe it clean to see if the leak stops.

If the leak stops, and the a/c still works good, then you are OK. If the leak doesn't stop, then the a/c will eventually stop cooling. If the a/c doesn't cool enough, its leaked too much already and you need to recharge the system. Meanwhile tighten the nut to see if you can stop the leak.

-=>Raja.
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  #5  
Old 06-30-2004, 12:32 PM
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Thanks for the tips...

It leaks 1 or 2 drops per day. The leaking fluid seems to be pressurized - that's how I discovered the leak in the first place. There was a hissing sound coming from the base of the valve (the valve itself seems OK), and I could see fluid and gas bubbling out. Is this part of the system under constant pressure all the time, or is it only pressurized while the A/C is running?

If I clean the area, it's oily again by the next day.

I tried an ineffective (but inexpensive) fix of putting a small amount of JB-weld epoxy around the base of the valve, hoping to seal off the leak. This didn't work - the bubbling fluid and gas forced the epoxy out of the way, preventing it from making a seal.
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1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD
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  #6  
Old 06-30-2004, 01:06 PM
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The system is always under pressure, though more pressure when the A/C compressor is running. Though your seeing dye or oil leaking out your also loosing refrigerant and if your system is r-12, the refrigerant is not cheap as it used to be. Dont know about Canada but in the states r-12 is harder to come by than r134. If you go to have your A/C system serviced there is a good chance the A/C service place will suggest to you that now is the time to convert your system to r-134. You need to read all the posts about r12 vs r-134 because most do not recommend the conversion. If you agree, then you want to have what r-12 is left in your system captured during servicing so it can be reused in your system once that leak is fixed.
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  #7  
Old 06-30-2004, 02:04 PM
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let me interject,


The cap is to keep the dirt out of the valve and hence a/c system. It's not meant to "seal" the system. Your car most likely needs a new shrader valve. This is a very common leakage point.

Do you need to discharge your system for replacement? *NO*. You can buy a special tool for R&R the valve with the system full and it should cost you about $25-35 plus $2-5 for the valve.

This is a 10-15 minute repair job!

Michael
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  #8  
Old 06-30-2004, 02:49 PM
ammdc7
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here's a weird question... What if the refrigerant leaked out while changing the valve, would the compressor oil leak as well? Or would you have to flush, evacuate and fill?
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  #9  
Old 06-30-2004, 03:16 PM
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Location: AL
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Look inside that little black cap and see if there's an o-ring in there. There should be one to act as a backup for the valve.

BTW, the pressure is LOWER in that hose when the AC is running than when it is off.
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  #10  
Old 06-30-2004, 05:02 PM
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The valve itself is definitely OK (as is the cap) - no leaks from inside the valve / cap at all. The nut (joining the black hose to the silver pipe) is also tight and dry.

The leak is definitely coming from the base of the valve stem, where the valve stem intersects with the hexagonal portion of the silver pipe (see photo in earlier post).

Is there any way to fix this without discharging the a/c system and replacing the entire silver pipe? Where does this silver pipe go?
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1989 250TD Wagon 5-speed, 160,000mi ::: Dark gray metallic / black cloth
1984 190D-2.2 5-speed, 287,000mi ::: Silver-blue metallic / black MB-tex ::: SOLD
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  #11  
Old 06-30-2004, 05:26 PM
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The silver pipe goes to the expansion valve.

It attaches just on the engine side of the firewall.

I hope you have small hands.
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  #12  
Old 06-30-2004, 07:33 PM
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Replace the line=)

You could take it to a hydraulic line shop and they can probably weld or silver solder it...

Yes, generally you loose some oil with a leak. Make to put a new drier on when you have it apart.

Michael
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