My son's 98 E300 has a bad AC leak. Today I had the chance to add some refrigerant to see what was going on. After getting up to about 1.4 bar of pressure, I turned the car off and heard a very obvious hissing sound from the left front. With a leak detector I was able to determine that the source of the leak is directly beneath the front washer tank...it's a very precise spot that sets off the detector.

Could anyone hazard a guess as to what's leaking and what's involved in effecting repair before we go any further?

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14 E250 Bluetec 4Matic "Sinclair", Palladium Silver on Black, 154k miles
06 E320 CDI "Rutherford", Black on Tan, 172k mi, Stage 1 tune, tuned TCU
91 300D "Otis", Smoke Silver on Tan, 142k mi, wastegate conversion, ALDA delete

19 Honda CR-V EX 61k mi
Fourteen other MB's owned and sold
1961 Very Tolerant Wife

Dryer is in that area along with some hoses. Pull washer reservoir out of way and you shold be able to find it.

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Jim

Confirmed, the dryer is directly beneath the left headlight. You have 2 sensors and 2 hoses at the dryer so lots of potential for leaks.

Note that MB updated the stub hose from the condenser to the dryer so be sure to order one if you end up replacing the dryer.

You may end up getting lucky and it’s just a loose connection.

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The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech

You can soapy water refrigerant leaks like any other air leak.

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1997 E300 Diesel - 222K miles

As a data point, the dryer on my w210 literally blew out due to rust.

Great point, the bottom of the dryer is exposed to the road. It sits in a circular opening in the body and would be exposed to road salt.

__________________
The OM 642/722.9 powered family
Still going strong
2014 ML350 Bluetec (wife's DD)
2013 E350 Bluetec (my DD)

both my kids cars went to junkyard in 2023
2008 ML320 CDI (Older son’s DD) fatal transmission failure, water soaked/fried rear SAM, numerous other issues, just too far gone to save (165k miles)
2008 E320 Bluetec (Younger son's DD) injector failed open and diluted oil with diesel, spun main bearings (240k miles)

1998 E300DT sold to TimFreeh
1987 300TD sold to vstech