Clogged evaporator drains.....Full of rusty metal...
 

:EDIT: EVAPORATOR DRAINS: Cruising to work today in my 83 300SD on a typical hot swampy south Florida morning. Made a U-Turn to get to my work and I could hear what sounded like water splashing on carpet. I looked to my right and a waterfall had opened up under the dash on the passenger side! Water was gushing out of the passenger foot vent!:eek: Got into my work parking lot, muttering and cursing under my breath as I walked to my desk. Went out at lunch to have a look see. Passenger front floor, rear floor and driver rear floor are all soaked. Pulled the passenger front carpet, pulled the panel that covers the transmission hump expecting to find a nonexistent, turned to dust drain line or something. First I saw that the drain line is different on the SD than other models that have a foam drain line. The SD's is rubber and it is easy to access. It was in perfect condition. Looking at the orientation and location of the drain, it was impossible to cause water to come out of the passenger foot vent if it were leaking. I made the observation that the outside of all of the black plastic that encompasses the air conditioning evaporator and air ducting was dripping with condensation. I pulled the drain line and shot a flashlight up it. I could see something up there...maybe some leaves. Stuck a screwdriver up there and gave it some good roto-rooter action. Water started pouring out of the drain.....all over the floor pan....:rolleyes: Along with the water was quite a bit of rusty metal. The drain was blocked with rusty metal bits and fine bits.

Sooooo, questions of the day are....

1) What would cause rusty metal bits in the evaporator housing area to the extent of clogging the drains

2) Is there a drain on the drivers side of the transmission hump that is clogged as well or is there only one drain the the passenger side that I just cleaned.

FYI, if you ever have a waterfall coming from under the dash with the ac on for a length of time.....you have clogged evaporator drains....

It's not necessarily a condenser just because it causes condensation. As counterintuitive as it might be, the subject component is actually an evaporator.

I actually knew that, yet I always say or write it incorrectly.....:rolleyes:
Good catch!
........Original post edited.......

Foam Drain Tube
 

Here is your answer on how to replace the AC drain on a 126.

http://www.peachparts.com/shopforum/diesel-discussion/193611-w126-where-water-coming.html

There have been other fixes. like cutting off the to off a plastic coke bottle for a drain. Not sure what to say about your debris/rust problem. may have to dig into the dash.

Charlie

One of three possibilities come to mind. Either metal parts of the evap itself are rusting, or the heater which is back in there somewhere too, or the firewall?

- Peter.

It would have to be the firewall, since the evap is aluminum and the heater core is either aluminum or copper/brass.

The heater core and the A/C Evaporator are in a plastic box. so Iam trying to picture how a rusty firewall or what ever might get into it. Unless something fell into the blower air intake area. but seems like it would rattle around in the squirel cage.

Charlie

Maybe its the squirel cage itself? I cant think of much else in the AC system that could rust. The car is rust free as far as I can tell.... Hmmmm.....

SD cage is also plastic, and I cannot fathom how metal could get in there... unless the air intake vent above is deteriorating, that's the metal that the front swaybar is mounted in, so if it's bad, it's a serious chore to get in there and fix!