AC doesn't drain 1986 560 - PeachParts Mercedes-Benz Forum

scotts560 · #1 09-19-2004, 09:40 PM

My 1986 560 drips water on my feet when driven with AC on. I checked 2 drains under car and they are open. There is no water under car when running. Where should I go from here?
Thanks, Scott.

maheath · #2 09-24-2004, 12:54 AM

There are actually 4 drain tubes in the transmission tunnel. I'm pretty sure that the two closer to the back are the A/C drains. Mine were plugged up pretty good. I ended up taking it to my Mercedes mechanic and he unplugged them from about $30.

If the tubes are clear, then the expansion valve might be missing it's insulation.

See http://www.dianasmercedes.com/TechnicalArticles/WetFoot.htm

balsa · #3 06-28-2006, 08:16 PM

My AC drain tubes are clear...the condensate is dripping from them not stronly but it does. Unfortunatelly condensate also drips on foot area drivers and passangers. My expansion valve is not insulated but I will do it very soon (passenger side).

What a about the passengers side driping will it stop when I insulate expansion valve?

I am very confused on this issue, since I went to a AC specialist today and he wanted to take the dash out saying that he needs to silicon some AC conections under dash so the condensate will no more drip inside the cabin but all will go down the dranage tubes. This is a very expensive repair. I dont want my dash to be dismantled and honestly I dont trust this mechanic much I think he is selling me a story.

Please advice since I dont want to develop a rust area in my floor plans,,,and the summer is here very hot now and AC is a must.

Thank you all for any input.

Balsa

1986 560sl with 120k miles.

cbdo · #4 06-28-2006, 10:46 PM

If you can get insulation on the cold lines without leaving airspace between the metal and your insulation, you're golden; no more condensation if you do a thorough job.

balsa · #5 06-29-2006, 08:10 AM

Quote:

Originally Posted by cbdo

If you can get insulation on the cold lines without leaving airspace between the metal and your insulation, you're golden; no more condensation if you do a thorough job.

Ok. Thank you very much for helping me on the matter. As understand the lower dash should be taken out to clear the space. I will insulate the metal lines on drivers side.

Is there something that should be insulated on the passengers side?

Thanks,

Balsa

ctaylor738 · #6 06-29-2006, 10:09 PM

How do you know that the drains are clear?

The easist way to make sure is to have all six blown out from underneath with compressed air. If that doesn't fix it, you may have some rust issues in your sheet metal around the evaporator.

balsa · #7 06-29-2006, 10:58 PM

Quote:

Originally Posted by ctaylor738

How do you know that the drains are clear?

The easist way to make sure is to have all six blown out from underneath with compressed air. If that doesn't fix it, you may have some rust issues in your sheet metal around the evaporator.

I had a rust issue in blower housing. Have cleaned that area and fiberglassed it. Also changed the gasket and plastic cover.

The condansate drips from 2rubber tubes ,...so they are clean..also other 2 are driping water when it rains. What are the other 2 tubes are for I never heard that they exsist? I will try to insulate AC lines with special thermo tape within the cabin. If this does not help I beleive that that I will have to look more deaply within the evaporator for rust.

Thanks, Balsa

balsa · #8 06-30-2006, 01:34 PM

1. Also to get the AC lines insulated in the cabin I beleive I should take lower dash pannnels and senter console pannels out? This way I will have more room to the job right.Although I have checked today and the lines are insulated with tape but not very good....That is why I still got the water on foot from condensate.

2.Does anyone know if there is some kind of seal on the point were rubber tubes goes from blower housing through the firewall and down to the drain tubes in transsmision tunnel?This tube lines are draining condensate from the evaporator housing. I beleive this area is the coolpit of all condensate water coming from the evaporator housing to the cabin and driping on foot. Any experiences in this area?

This problem frustrates me even more since today I have seen that the large amount of condansate is driping from the floor pannel next to the gas pedal. But it also drips from the drain tubes but it drips more on the place on front pannel (which means the drain tubes are clean). I will solve this very small rust hole in the floor but not sure I will solve the problem.

Regards to all and thanks for all the feedback on this issue,

Balsa

balsa · #9 07-18-2006, 04:13 PM

Finnaly have fixed the AC condensate dripping to the footwell area. Unfortunatelly it was none of the disscussed above solutions. As always I get the worse case .... The plastic evapurator housing had small cracks on both sides. I glued it with a special windshield waterproof glue and now everything drips to the drains as it should be.

Balsa