Air conditioner Drain Hoses
 

Gents,

Where would I locate these hoses to see if they are clogged/replace them?

Can find nothing in MB CDs or my Haynes manual; search revealed no info re. location of these beasties.

What kind of car are you asking about?

AC Drain Hose
 

Sorry,

1990 300E.

The drain hoses on this car exit straight out the bottom of the heating/air conditioning box, through holes in the transmission tunnel, and onto the ground. I don't believe it's possible to see or access them without some dissasembly.

The hoses themselves are made of flimsy, insulated foam. They will most likely instantly disintegrate when you touch them. I replaced mine while the heater box was out of the car (for a/c evaporator replacement) with lengths of rubber hose purchased at a local big box home store. I think 3/4" was the right size, but am not certain.

For two reasons it seems unlikely to me they are blocked. First, there are no turns - the drain hoses dump straight out the bottom of the heater box, through the firewall, and onto the ground. (Well, more like onto the transmission, but who's counting.) There are no turns in the drain hoses, unlike other cars I've seen have clogging problems. Second, the hoses are relatively large diameter - this would seem to help prevent clogging.

You *might* be able to see the drain hoses by removing the ashtray and looking under the heater box. They can probably be accessed by removing the carpeted side panels of the center console. Might even be able to see them from under the car, looking up by the transmission - but I doubt it.

Attached photo shows my 124 wagon disassembled for evaporator replacement. Red arrow indicates the passenger side drain hole - there's an equivalent on the driver side. Note position of the gearshift lever for reference.



- JimY

evap drain hoses
 

when I replaced the evaporator on my r129 , I replaced the foam type hoses with regular off-the-shelf RIGID clear tubing from hardware store. the access hole is by the bell housing area. My design has 2 hose exit holes. I fished the rigid hose from the bottom and my wife helped me connect the end of it to the evap box- inside the car. I then tightened the hoses with zip ties. You can also use hose clamps, but there are no internal pressures here. Therefore, snug fit is all that is needed. Hope this helps.

Drain hoses
 

Thanks jcyuhn and a2aa.

This looks a bit more involved than I thought.

I had seen one drain hose from underneath car - by trans pan - and did not realize they were that far toward front of car.

More substantial hose sounds like good idea also, as I had one that had worn out on my daughters 300D (replaced by mechanic back in days before I found out how satisfying 123s, 124s were to work on.)

Thx

I'm resurrecting this thread because it ideals exactly with my question.

My A/C drain tubes in the transmission tunnel have rotted away too. It looks like there is a spring extending from the hole into the tunnel, maybe one inch long. They look like they would be used to push the tubing over and secure them some what.

I thought about using foam tubing but then doesn't a lot of heat get pushed through the tunnel if you have the weather shields attached to the bottom side of the vehicle? My thought is the heat would not be great for the foam tubing. Maybe some clear plastic tubing would be better.

I couldn't really tell, but there doesn't seem to be a lip for the tubing to seal against up there.

How have you guys dealt with this issue?

That is a great picture btw, really show how the drain workd form the topside. Thanks!

I just replaced one on my '95 wagon. I used 5/8"-I think- clear vinyl hose and chamfered the mating end quite a bit. After removing the remains of the old hose I slipped the new piece down into the tunnel then pushed it onto the hose bib with pliers. Warming the hose helps a bunch.

I just checked that you can pull panel #8 below and get access to the hose.
I pulled the left side only.
I assume the right side will show the drain hose also.
Mine do not leak but at least I know what to do know when they do.
I might do it as a preventative measure this winter or fall.

http://i31.photobucket.com/albums/c3...00062_0165.gif

I didn't realize there was a leak until I removed the moulded carpet to clean it. Item #8 can be removed easily to access the drain tube.

It is true I don't want to wait until things get moldy, hence my fall or winter project.

Does anyone know the OD of the drain off of the evaporator housing and the ID of the opening into the transmission tunnel?

Home Depot has a large assortment of drain hoses on spools...maybe one of them would work well.

I used a piece of 5/8" clear vinyl hose. It fit the evaporator and the 1" hole in the trans tunnel well.

ac evaporator repair
 

Thanks for this information! 5/8" is the value I needed!

Recycled
 

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