Dear Fellow Brickboarders,

May this find you well. I just started to use newly-recharged aircon on a 93 940. I noticed what is obvious: the water removed from in-cabin air drips onto the passenger side frame rail, in front of the fire wall.

I did the following modification of the drain - so that the water does not fall on the frame rail - and am interested to know if it is sound.

I took a 10" length of 5/16 clear vinyl tubing (thinwall). I inserted one end of this tube 1/4" into the condensation drain opening and secured the tubing with butyl rubber tape. I formed a doughnut of butyl rubber tape and pressed it into place, over the mouth of the drain opening.

I ran the bottom of the vinyl tubing on the inside of the frame rail (the side closest to the engine), following the curve of the firewall down and backwards. I secured the tubing with a strip of butyl rubber tape, pressed into the angle where the firewall and frame rail meet.

Butyl tape clings strongly, but is removable. Over time vinyl tubing deteriorates, so this is not a 20-year solution.

Am interested to know if anyone else has done this, or if there are good reasons not to do this.

Thanks in advance for your guidance.

Yours faithfully,

spook

Spook. It sounds like a good solution. I had a problem with the condensate leaking "back" into the passenger footwell because the seal around the drain grommet was in poor condition. It took me quite a while to figure out how the carpet was getting so wet. I originally thought the heater core was leaking but there was not anti-freeze present.

I finally fixed the problem by caulking the outside of the drain grommet with silicone. Your solution sounds better.
--
93 945 96K , 94 940 100K

Dear lpsage,

Good p.m. and hope you're well. Thanks for looping back. Presuming you applied the caulk to a clean and dry surface, it should last just about for ever.

I installed the tubing because I didn't want condensation dripping onto the frame member. If I have to replace the vinyl once a year, I can do that. The butyl will allow me to pull the vinyl free, and to insert a new length. I may upgrade to a translucent nylon, which will last longer but be harder to fit. Nylon is stiffer than vinyl and takes a "set".

Yours faithfully,

spook

Hello Spook,

Good idea. I was thinking about doing about the same. I thing the hose which is about the diameter of a pencil has a too small of a diameter and is also too long. You will get a buildup of slime, mold and dirt in there and may clog up quickly. I think a larger diameter, shorter hose would work better.
--
Tom F. Three 940s. '93 T-Rex now running. Mods, RainX. Lien holder on two more (the kid's). Rust In Pieces, '78 245

Dear Tom,

Good p.m. and hope you're well. I share your concern about the drain tube getting plugged. That's why I used clear vinyl (easy to inspect) and adhered it with butyl rubber (rather than some more permanent method).

I wanted to use a larger diameter hose. Because the drain stub does not project more than 1/8" beyond the grommet, there is no where to attach a wider hose, i.e., one that goes over the drain stub.

I could cut-off the 5/16" hose and put a wider diameter hose over the stub of 5/16" hose. That would leave only a very short narrow section. Do you think that would improve matters.

Thanks for your suggestions.

Yours faithfully,

spook

If only that tube was a little longer.

My ’93 and ’95s are the same way with that tube sticking out 1/8”. The ’93 T-Rex had started to develop rust at a body seam directly below it. I’d run the hose out and forward a little and down then clip it to side of the frame somehow. That way the hose is totally visible.

Ten minutes later…
I looked at a few different diameters. This is just an idea and it’s easier said than done: Epoxy a 1” long piece of PVC or copper pipe and attach a 20” piece of 5/8” or so radiator hose or clear hose about 20” long. The end will be well forward of the control arm bracket to keep it away from the exhaust and clipped to the side of the frame. The epoxied pipe will be the weak link. I’ll try using some of my pack-rat junk.
--
Tom F. Three 940s. '93 T-Rex now running. Mods, RainX. Lien holder on two more (the kid's). Rust In Pieces, '78 245

Longevity of vinyl will not be great due to the proximity of the hot exhaust system. I understand the desire to see the inside of the tube, but I fear that it will embrittle sooner rather than later. Keep us posted.

Dear Steve,

Good p.m. and hope you're well. I suspect you're right about longevity (shortevity?) of the vinyl. Embrittlement may not matter a whole lot, as there is little or no movement. The drain port is fixed and the hose is bedded into an angle in the sheet metal.


It is as far from the cat as I can put it. If it lasts a year - and doesn't get plugged - I'll be happy. Replacing it is easy, as the tubing can be pulled away from the butyl and replaced. No tools needed, except for a knife to cut the vinyl.

I'll report in due course.

Yours faithfully,

spook