And you wonder why the front sills and floor rust ?

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TimU
Posts: 280
Joined: Tue Dec 14, 2021 2:16 am
Location: Sydney

Re: And you wonder why the front sills and floor rust ?

Post by TimU »

Update:
I extended the sunroof drain hose outside the sills LIKE BMW SHOULD HAVE!
Image

It's a bitch of a job to do on your own, but a second set of hands really helps.

The good news is that the area is accessible without needing to remove the front guards or door sills. Only the wheel-well splash guard needs to be removed - Pretty easy.

I was also happy to see there is no rust at the common points, but I gave the area a thorough clean and anti-rust coating for good measure.

Tips to help:
  1. There are 3 holes to pass through.
  2. Feed a coat hanger wire from the speaker hole at the top, down through 2 holes inside the body to the lower door sill.
  3. Use a 2nd coat hanger wire to fish the 1st out of the front hole.
  4. Feed the new tube down over the wire, using it as a guide.
  5. Fiddle around at the front hole to guide the tube out. This is where a 2nd person comes in handy.
  6. Join the tubes however you see fit (see below).
  7. FOLD the original tube back on itself when feeding the new tube down the hole. If you don't fold it straight, your whole tube length will be twisted and blocked.
Joining tubes:
I used gaffa tape. I tried using Heat Shrink on my first attempt, but it failed to hold together on the pull through.
I also considered a barbed reducer fitting, but there isn't much room to work with down there, and a reducer fitting is unfortunately not flexible enough to manipulate back into the hole.

I'll let the pictures speak for themselves.

Drain hose in action
https://imgur.com/AyCd0pT

Work log:
Remove the Splash guard inside the wheel-well
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Pretty filthy!
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Nice and clean, thankfully no rust.
Image

Factory drain hose looking into the speaker hole
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Factory drain hose looking DOWN through the speaker hole
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Drain hose pulled out of the speaker hole
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10mm vinyl hose. Best to feed DOWN from the top and fish it out of the lower hole.
Image

Taped up with Gorilla tape
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Trim to desired length.
Image
04/1986 635csi Euro spec
Australian Delivered, RHD
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Sbeaud
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Joined: Fri Jan 04, 2019 9:38 pm
Location: Okahumpka, Florida USA

Re: And you wonder why the front sills and floor rust ?

Post by Sbeaud »

Wow. Another great post Tim. Thanks so much for documenting so well - especially for those folks like me that need pictures.

Scott
1988 M6
songzunhuang
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Re: And you wonder why the front sills and floor rust ?

Post by songzunhuang »

I have to second the above comment. Thanks so much. With the clear pictures as a guide, I’ll tackle mine - if the rain here in Northern California ever stops. Meanwhile, I get to empty buckets of water on a regular basis. I filled a 2 gallon bucket over the course of a day!
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Song Huang
1984 633CSi
Last 7 of VIN: 6997383
Ronnie Wilson
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Location: Liverpool uk

Re: And you wonder why the front sills and floor rust ?

Post by Ronnie Wilson »

Hi

Well done 👍🏻😀
Ronnie
Liverpool uk.
1986 635csi.
Bronze Beige Metallic.
songzunhuang
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Re: And you wonder why the front sills and floor rust ?

Post by songzunhuang »

songzunhuang wrote: Sat Jan 14, 2023 9:14 pm I have to second the above comment. Thanks so much. With the clear pictures as a guide, I’ll tackle mine - if the rain here in Northern California ever stops. Meanwhile, I get to empty buckets of water on a regular basis. I filled a 2 gallon bucket over the course of a day!
Commenting on my own comment! I wanted to close the loop on what I did to my car. I posted the process and pictures here. You can see how much water I was getting! Scroll down about halfway to see the details of how I took care of each side. The first post is entitled "Water Drain Tube Fix".

viewtopic.php?t=25858&start=1075

It finally stopped raining and I took care of both sides. Weirdly, my driver side fender didn't have a hole at the bottom, but there was a gap sufficient to let the water drain.
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Song Huang
1984 633CSi
Last 7 of VIN: 6997383
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sansouci
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Re: And you wonder why the front sills and floor rust ?

Post by sansouci »

Minor add to the solution: put a ss hose clamp where the hose exits the bottom drain to prevent it withdrawing back into the cavity.
Sansouci
84 E24 633Csi Auto, Bronzit/PearlBeige 6997510
93 E32 740il M60 Auto, Alpenweis/Ultramarine
60 528i M30 5-speed Green/Beige (crushed)
71 240Z 4-speed White/Blue (rusty & sold)
65 396 Chevelle 4-speed, Marina Blue/Black (stolen)
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