Alright guys, my AC S500 is blowing hot air in this hot summer. The evaporator temp is over 90F during the day. I plan to inject refrigerant dye in there to see if I can find the leak. Is this the plan?

Any good hearted DIYer out there to guide me? Any help is appreciated. Thanks

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93 Toyota Corolla 177K
95 S 500 coupe 82K
92 400E 180K (SOLD)
94 E 420 150, blown gaskets (SOLD)
http://www.kanio.net/mercedes_signature.jpg

Is your CCU digital? If so, you may be able to pull up the AC "Actual Values" and "codes".

Search "SteveBFL and AC Diag Continental Imports article"

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Terry Allison
N. Calif. & Boca Chica, Panama

09' E320 Bluetec 77k (USA)
09' Hyundai Santa Fe Diesel 48k (S.A.)

I pulled the code, no error was detected from the system

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93 Toyota Corolla 177K
95 S 500 coupe 82K
92 400E 180K (SOLD)
94 E 420 150, blown gaskets (SOLD)
http://www.kanio.net/mercedes_signature.jpg

First thing you need to do is find the leak. Inspect the AC system components and look for oil leakage. Most likely on the high side pressure hose leading from the compressor to the condenser coil. If you don't see any oil leak then it might be a leak in the evaporator. That usually requires a sniffer. Put a small charge of freon into the system and begin hunting down the leak. There is an auto AC business that will locate the leak for a price. Cool Flow, owner name is John Noble. Located near 290 & Mangum.

After you find the leak, fix it, recharge and stay cool.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

I have put dye in the system. I had to pump quite a bit of freon in there to get about 12 bars of pressure. It started with 2 bars in the beginning. I saw a slight amount of green dye around foam hose underneath the passenger. The hose is made of foam and has white coil spring in it.

Is the hose the evaporator drain hose?

I plan go to Cool Flow this week to verify that I have a leaky evaporator, anyone had good/bad experience with Cool Flow?

__________________
93 Toyota Corolla 177K
95 S 500 coupe 82K
92 400E 180K (SOLD)
94 E 420 150, blown gaskets (SOLD)
http://www.kanio.net/mercedes_signature.jpg

How much is "quite a bit" ?

Yes the hoses you describe are the evaporator drain tubes.

Cool Flow does quality work and their prices reflect that.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

The going price for a W140 evaporator replacement is around $5k. The car was built around the evaporator and you pretty much have to rip out the entire dashboard to do it. Take a look:

http://pages.prodigy.net/jforgione/AC_Seal.html

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"It's not about how fast you can go, but how well you can go fast."

Bob in Richmond

'97 S320 (LWB), Ruby Red Metallic, 73k miles
'97 S420V, Smoke Silver Metallic, 155k miles

OH MY GOD!! Glad I don't own a 140.

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I got too many cars!! Insurance eats me alive. Dave

78 Corvette Stingray - 3k
82 242 Turbo Volvo - Manual - 270k
86 300e 5 speed manual - 210k
87 420sel - 240k
89 560sl - 78k
91 420sel - 205k
91 560sel - 85k
94 GMC Suburban - 90k
97 Harley Davidson Heritage Softail - 25k
00 GMC Silverado 1 ton 30k

Nice Collie! Dogs make the best companions while working on an MB in the old Man-Cave.

- JimY

I was glad my W124 never experienced this failure (it's common on W124s too).

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08 W251 R350
97 W210 E320
91 W124 300E
86 W126 560SEL
85 W126 380SE Silver
85 W126 380SE Cranberry
79 W123 250
78 W123 280E
75 W114 280

DAMN, that's what I have to look forward to. I will buy the parts and do this myself. I plan to start the dissassembly this week.

Any one has a guide or video that other member posted? I will get as much help as I can beg for.

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93 Toyota Corolla 177K
95 S 500 coupe 82K
92 400E 180K (SOLD)
94 E 420 150, blown gaskets (SOLD)
http://www.kanio.net/mercedes_signature.jpg

You know, I look at the 140s and I really want to buy one. But the more I read stuff like this and see the pictures of the procedure...I think I'll stick with my W126 300SEL. It's not as refined as the 140, but it is also a lot easier to work on.

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I'm sick of .sig files

Good decision. Unless you find a very low mile beauty, the W126 is the way to go. Back when I had the 420SEL I solve could any problem with hand tools and the occasional coat hanger. The creature comforts of the 140 make the car feel light years ahead of the W126, but when the gremlins begin to appear....... you'll be begging for that 80's engineering.

Amen, Brother!

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"It's not about how fast you can go, but how well you can go fast."

Bob in Richmond

'97 S320 (LWB), Ruby Red Metallic, 73k miles
'97 S420V, Smoke Silver Metallic, 155k miles

I have to thank dpetryk on his advice of Cool Flow. John helped me locate the leak and it thought it was the evaporator. We put the refrigerant probe on the outlet vent and nothing. We had to dig around the car and found the leak at the pipe. It is the AC line from the evaporator to the compressor. The line is always cold and insulated. The insulation traps the water and always keept the pipe wet. Over time, the line got rusted and started the leak. I have ordered the parts and hopefully that is the only thing wrong with it.

I have attached a picture of the pipe and the location of it.

Attached Thumbnails

   

__________________
93 Toyota Corolla 177K
95 S 500 coupe 82K
92 400E 180K (SOLD)
94 E 420 150, blown gaskets (SOLD)
http://www.kanio.net/mercedes_signature.jpg