=====A/C Evaporator Drain Tube Replacement ===== ====on the 1984 300SD (W126)==== ===by ""bodyart27""=== (edited by whunter) ===4/02/09=== ---- Just got back from a road trip to Houston (from Dallas) and when unloading the car last night I noticed the carpet behind the driver's seat (where the rear floor mat lays) was saturated. Real wet. Pulled back the carpet and put a fan in the car overnight (still damp this morning). Not rusty - had to be recent. Hmmmm. I opened the sunroof and poured water into the rails on both sides (poured in the middle). Car took a pee onto the pavement from the rear wheel wells. Drains were not clogged. That seemed right. I got nailed in a rain storm in Houston driving in on Friday, and overnight sitting in a parking lot. Maybe a door ajar? Window cracked? Water forced in somehow? Initial look at the trunk - looked dry. I can't recall anything (like a water bottle) that could have leaked back there. If water came in on the back edge of the sunroof - where does it go? Can condensation from the A/C get back there? the front floors / floor mats are dry. Any thoughts? Something to look for? I guess if it only does it once I'll rack it up to a door/window ajar? But, long story short, I pulled the panel back, found the A/C evaporator drian tube easily and installed it. The old tube had deteriorated to the point where I could see the inner coil spring that is inside the foam of the drain tube (inner spring is there so it doesn't collapse as there is a wiring that crosses over it). I really think this could be designed better. But, then again, it lasted 23 years. If you click the "buy parts" link and look up a/c evaporator tube you'll see what I'm talking about. [[http://catalog.peachparts.com/ShopByVehicle.epc?q=1984-Mercedes--Benz-300sd-Climate--Control&yearid=1984%40%401984&makeid=63%40%40MERCEDES+BENZ%40%40X&modelid=6208%3AMBC%7C1510%3AED%7C10000134%40%40300SD&catid=242213%40%40Climate+Control&subcatid=242275@@A%2FC+Evaporator+Drain&mode=PA Click Here for Fastlane Link]] ---- So finally got some time to add some pics. First pic is just the new A/C drain tube. Very odd construction - not too impressed, but the original did last 23 years. http://www.peachparts.com/diy/w126evapdrain/01.jpg Inside the spongy foam tubing is a spring that prevents it from collapsing. http://www.peachparts.com/diy/w126evapdrain/02.jpg There is a wiring harness that goes across the tube, so I guess the engineers wanted to be sure there was no condensation on the outside (thus the spongy foam). http://www.peachparts.com/diy/w126evapdrain/03.jpg Old and new drain tubes http://www.peachparts.com/diy/w126evapdrain/04.jpg ---- As you see in the pics: **1.** You remove the kick panel and knee bolster (the panel that goes above your knees under the steering column) to see the drain tube, not too difficult. ~- For orientation, that is the gas (diesel?) pedal on the left of the picture. http://www.peachparts.com/diy/w126evapdrain/03.jpg **2.** There is a wiring harness that is strapped with a reusable zip tie over the drain tube, I suggest unplugging the top connector and loosening the zip tie to make it easier to remove the tube. **3.** There is an ivory colored ring clip at the top of the tube, the tube had deteriorated so much that I just pulled it off the connector at the top, clip and all, then I undid the clip (hinged on one side, just a hook clasp on the other). ~- The clip is pretty darn tough to close after putting the new tube on. **4.** The drain fitting on the A/C evaporator has a little lip (like on a radiator). The clip goes past the lip (like putting a hose clamp on a radiator) so the tube won't back off. **5.** You thread the tube under the wiring harness and poke the rubbery end into the transmission tunnel. That's all there is too it. ---- **Note:** The Mercedes Benz evaporator drain part numbers are: LEFT MB# 126 830 11 96 RIGHT MB# 126 830 04 96 I have had some wood blocks under the carpet to get the SD to dry out. So far so good! [[http://www.peachparts.com/shopforum/showthread.php?t=193611 Discuss this DIY here.]] **-""bodyart27""** ---- CategoryDiy