brad_c43

So I know I have an AC leak but for the life of me i cant find it. I have dye in the AC system and a UV flashlight but no where in the engine bay or the interior of the car can I find the leak. what are some common areas on this car for the AC to fail? thanks!

DRBC43AMG

I had the same problem, but finally found the leak. It was behind one of the electric fans. It was impossible to detect until the condenser and electric fans were removed.

See my thread here: https://mbworld.org/forums/c36-amg-c...ic-clutch.html

Sulaco

The evaporator is the weakest point. It's part of the low-pressure side so it doesn't respond well to having too much pressure in the system.

Too many people just dump more freon in the system thinking it was "low" when in fact it needed a new condenser or receiver drier, this added freon brings the pressure up too high and you blow a hole in the evaporator. And out comes the entire dash to fix it. I did this job myself but it took 2 entire days. Shops charge $2500+

You better pray it's the compressor or condenser.

benzslo

98% of time it's condenser. Pull the top support for the radiator remove 10mm bolts holding condenser to radiator to wedge apart a little, look down you'll see it, have to look on rear side of condenser should only take 5 minutes to do this.

JohnnyRock

Great time for this thread, my AC doesn't work for squat yet again. I had it "fixed" at a local euro shop last year, but yesterday I turned on the AC and was greeted by 20 mins of blast furnace air.

Do those "off-the-shelf" AC leak detection kits work? Or do I need a pro to do it?

DRBC43AMG

When I get a refill, the technician always fills it with the appropriate gas (certainly not Freon as that is a BIG no no in this part of the world...), some oil to keep the compressor lubricated and dye so that if the pressure drops you can look around with a UV light to detect the source of the leak.

I'm 90% certain your condenser has a leak, so that will need to be changed. Change the evaporator/dryer at the same time....

Go check my thread. See post #2 above for the link

JohnnyRock

Not only did I check your link, I subscribed to it!

Just to confirm, when you say evaporator/drier, you are referring to this part

Do I need to get a O-ring kit as well?

DRBC43AMG

Exactly and take the O rings kit. 4 of them in two sizes
If you change the condenser, make sure to get the new valve also and the two O rings to connect the two bottom pipes and hoses...

brad_c43

Pulled the radiator support out but I couldn't see any leak. I did notice I have the original condenser so I'm probably gonna bite the bullet and replace it

JohnnyRock

PSA: For what it's worth, RockAuto.com seemed to have a wide selection of different manufacturers for Benz parts. Prices were also lower than Autohaus/Pelican/ECS, etc. (which have been my normal, "go-to" parts stores)

mickey13

my a/c problem was the compressor. i bought a rebuilt unit from these guys. very cheap, lifetime warranty, no core charge. works great think i paid just over $100
https://www.compresoresmiami.com/

brad_c43

Im almost pretty sure it has to be a leak and not a failure of a part because when i add the r134a with dye to the ac it blows very cold! but after a few days it gets warmer and warmer but i cant find the leak. probably will check rockauto for a new condenser and call it a day

JohnnyRock

Weird issue on mine...One day, the AC doesn't work, then, next day, it does! Still shaking my head on this one...

DRBC43AMG

Don't forget the receiver / dryer while you are in there. Not expensive and eliminates possible fault area. Also don't forget the O rings....

DRBC43AMG

Any fault codes? Electromagnetic clutch perhaps?

brad_c43

I had my car ac looked at by an older mercedes mechanic down in titusville and he showed me that the dryer was fairly newish looking. do you think i should still replace it?

mickey13

check the codes on the climate control unit

https://mbworld.org/forums/c36-amg-c...control-q.html

k649

@Sulaco did you change the evaporator on an X164 car? can you share the instructions, pictures, tools, etc? thanks!

Sulaco

Negative. I've only done this in one car, my 1994 C280, and this was like 13 years ago.

If it happens again, I'm paying a shop whatever it takes to fix it. I'm not doing that job again. At the time, I was poor with no choice and my wife was pregnant. Now? I'd rather set the car on fire.

k649

thanks for the clarification. I searched x164 and this thread popped up as a related thread.

my old x164 seems to have a leaking evaporator, as the water drain hole showed some UV dye there. An indy shop quoted $3000.

i'm thinking of doing it myself as the part is only $150. it looks like a very tedious and time consuming job, but nothing greasy or dangerous. which part of the job you hate most?

Sulaco

it's tedious, that's the main rub. Just Google x164 dash removal videos and take your time. Carefully log what bolts nuts or screws go where and put things back where they go. Look for anything else that might need replaced while you have it apart, like vent actuators or the heater cote. You don't wanna have to do this kob again later