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Sunroof drain tube design flaw

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  #1  
Old 12-31-2022, 07:33 PM
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Default Sunroof drain tube design flaw

I'm currently in the middle of finding and fixing the leaks in my 99 Disco 2. I'm starting on the rear sunroof.

I started by replacing the sunroof with a good used one. The PO tried to silicone or flex seal it shut, which didn't work. Rather than trying to clean up all that junk I just pulled one from a Disco at Pick N Pull.

I cleaned up the roof so it would sit properly and installed the new sunroof. I also cleaned out the drain pan and checked the drains and they seemed to be flowing. But not exactly draining.

The next day it was still leaking from one of the holes in the pan, so I popped off the rear light and found the drain tube. Using a little suction I was able to get water to flow out, and nothing came out but water. So the drain wasn't blocked, but it still wasn't draining.

Since I had removed most of the side trim to get the rear carpet out to dry it out I pulled the trim completely free so I could see what was going on with the drain tubes.

Man, what a mess. If this is how they came from the factory I'm surprised they ever drained properly.

I might have had to take my fluid dynamics class twice, but I at least remember that water flows downhill. And the larger the water column the more pressure on the water.

The way these tubes were routed they never drained. Water just pooled in the bends and the holes in the drain pan became the lower point in the system.

So I pulled them loose and rerouted them. I'm pretty sure that at some point in the DIsco 2 run they figured this out and rerouted them, because the 2003 that was at Pick N Pull wasn't leaking. If anybody has a later Disco 2 and happens to know how their drains are routed I'm curious, I pulled the drain tubes out of the one in the hard so I can't check.

To add insult to injury the drain tube on the passenger side was even pinched by the plastic rivet that holds the trim on!

I'm leaving all the trim and carpet out until I know the drains are working properly. Next up is the front sunroof. Then I need to find a new headliner, the PO ripped this one apart trying to find the leaks.

This might be common knowledge for those more experienced, but I didn't see anything about it. So hopefully this helps someone else fighting sunroof drains.


Driver side drain as found.

Passenger side

After re-routing. The water at least now drops 6" before flowing horizontally. I'd still like to keep it from going back up before exiting at the rear.
 
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  #2  
Old 01-01-2023, 12:42 AM
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I found this out when I did my headliner and replaced the drain corners. The front drained very well, but not the rears. I figured just re-routing doesn't fix the problem completely, it always leaves some bend where water gets trapped. You need to insert elbow fittings at the point where the drain tubes go through the body above the tail lights.
https://landroverforums.com/forum/di...ow-fix-111260/
 
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Old 01-01-2023, 05:15 AM
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When i did mine the pipe was black so my question is are they the original hoses, as the routing is not the same as mine
the front and rear, you will notice you have put them were mine are fitted from new


 
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Old 01-01-2023, 04:47 PM
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Originally Posted by Discorama
I found this out when I did my headliner and replaced the drain corners. The front drained very well, but not the rears. I figured just re-routing doesn't fix the problem completely, it always leaves some bend where water gets trapped. You need to insert elbow fittings at the point where the drain tubes go through the body above the tail lights.
https://landroverforums.com/forum/di...ow-fix-111260/
Thanks! I saw your post earlier and couldn't figure out where you put the elbows (then I couldn't find it again). Now it makes sense. You put them where the hose bends 90 degrees to go out near the taillight. That totally makes sense. I have been trying to figure out how to keep the hose up a bit higher so there isn't a bend there. But I will just try those elbows. Great solution!
 
  #5  
Old 01-01-2023, 04:48 PM
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Originally Posted by frostythor
When i did mine the pipe was black so my question is are they the original hoses, as the routing is not the same as mine
the front and rear, you will notice you have put them were mine are fitted from new
The hose in the 2003 at the wrecking yard was black. And I think it was routed where yours is. So I believe they made a running change at some point.

I also noticed they added a clip behind the taillight to hold the hose on the later model, it's not there on my 99.

What year is yours?
 
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Old 01-02-2023, 02:34 AM
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My hose just hangs down below the rear light cluster about 12 inch
 
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Old 01-02-2023, 10:29 AM
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I found the same thing when I removed the headliner to paint it 13 years ago. I rerouted the tubing similarly to what you did to eliminate the uphill segments of the run.
 
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  #8  
Old 01-02-2023, 11:54 AM
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Maybe in England where they designed these they don’t get much rain?😂
 
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Old 01-02-2023, 12:12 PM
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Originally Posted by Harvlr
Maybe in England where they designed these they don’t get much rain?😂
Do you call that "designed" ? Designed to fail ?
 
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Old 01-03-2023, 10:38 PM
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Originally Posted by autoarcheologist
Thanks! I saw your post earlier and couldn't figure out where you put the elbows (then I couldn't find it again). Now it makes sense. You put them where the hose bends 90 degrees to go out near the taillight. That totally makes sense. I have been trying to figure out how to keep the hose up a bit higher so there isn't a bend there. But I will just try those elbows. Great solution!
The elbows make a big difference and cost a few Dollars only. Before I tried different routings for hours and tested them, but no satisfying improvement. The only routing that would work well is in front of the alpine windows, but that's a theoretical solution only.
 


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