Advice needed - Rust repair and tracking down leak

hardebeck

Member
Jun 29, 2023
11
6
Phoenix, MD
I'm thankful that this 92 D1 has very little rust, all things considered, but I noticed the pad under the rear carpet was wet after a recent rainstorm and saw some rust on the floor panel. I stripped everything out this morning to take a closer look. Most of the rust spots are surface but there are a couple places, especially the left rear, where it looks like water has sat for quite a while (this is where the pad was wet). 2 questions:
1. Recommendations for repair - should I cut out and replace the rustiest portions, or just grind, prime, and paint? The panel seems to be structurally sound for the most part.
2. Before I undertake any repairs, I need to locate and correct the leak. Any recs for where to look? I can't find any obvious points of entry. There is no rust or water stains that I can see anywhere above the floor but I don't see where water is getting in and under the carpet. Figured there may be a "usual suspect" that I can get clued into.

I also noticed a couple wires badly worn through on the fuel tank sending unit. The fuel gauge works but I'll repair those before I button everything back up. (fyi, that's Kroil on the fittings just to dress the rusty bits)

Thanks all!IMG_4615.jpegIMG_4616.jpegIMG_4617.jpegIMG_4618.jpegIMG_4619.jpegIMG_4620.jpeg
 

hardebeck

Member
Jun 29, 2023
11
6
Phoenix, MD
Mine leaked from the rear door seal, at the top of the door, and made a wet spot on the drivers side rear corner.
Thanks. That would track with where most of the rust is. I’m going to hold off repairs until we have a good rain to see if I can find the source. I’ll take a closer look at the seal.
 

Gordo

Well-known member
If it was mine, I would hit the worst spots with a screwdriver and if no holes pop up, I’d wire brush (on a grinder) the worst rust off, ospho the rust, and repaint it. If any of the metal has holes or is real thin, then I’d cut that section out and weld new metal in. It doesn’t look bad at all for a 92. May as well check the front pans while ur at it too. Gordo
 
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DiscoClay

Well-known member
Mar 18, 2021
443
89
Chapel Hill, North Carolina, USA
I'm thankful that this 92 D1 has very little rust, all things considered, but I noticed the pad under the rear carpet was wet after a recent rainstorm and saw some rust on the floor panel. I stripped everything out this morning to take a closer look. Most of the rust spots are surface but there are a couple places, especially the left rear, where it looks like water has sat for quite a while (this is where the pad was wet). 2 questions:
1. Recommendations for repair - should I cut out and replace the rustiest portions, or just grind, prime, and paint? The panel seems to be structurally sound for the most part.
2. Before I undertake any repairs, I need to locate and correct the leak. Any recs for where to look? I can't find any obvious points of entry. There is no rust or water stains that I can see anywhere above the floor but I don't see where water is getting in and under the carpet. Figured there may be a "usual suspect" that I can get clued into.

I also noticed a couple wires badly worn through on the fuel tank sending unit. The fuel gauge works but I'll repair those before I button everything back up. (fyi, that's Kroil on the fittings just to dress the rusty bits)

Thanks all!View attachment 65521View attachment 65522View attachment 65523View attachment 65524View attachment 65525View attachment 65526
That pump wiring looks like it needs some help! :)
 

DiscoClay

Well-known member
Mar 18, 2021
443
89
Chapel Hill, North Carolina, USA
My worn rear door seal (and sagging door) combined with the rear AC drain being plugged appears to have caused almost identical rust.

Also, at least with the NAS wagons, the dense foam floor mat, with it's contour-matching shape REALLY traps moisture! I think it's worth considering just removing it completely and spraying sound deadener directly onto the repaired floor.

Let us know what you find and what you do! :)
 

hardebeck

Member
Jun 29, 2023
11
6
Phoenix, MD
My worn rear door seal (and sagging door) combined with the rear AC drain being plugged appears to have caused almost identical rust.

Also, at least with the NAS wagons, the dense foam floor mat, with it's contour-matching shape REALLY traps moisture! I think it's worth considering just removing it completely and spraying sound deadener directly onto the repaired floor.

Let us know what you find and what you do! :)
I couldn’t find an obvious source of water intrusion but the last rain was pretty light. I may need to simulate a downpour with a garden hose before it gets any colder. No obvious rust or water tracks on the perimeter behind the trim panels. I used some abrasive wheels on a drill (the red plastic 80 grit ones) to remove the loosest rust and get to bare metal where I could. Cleaned everything up with acetone and then coated with a layer of Ospho. Going to let that dry for a few days and then I’ll prime and paint. I couldn’t find any spots that were rusted through but there are several “bumps along the edges that look like rust is happening below the pan and pushing up. I figure in a few years I’ll go back and replace all the sheet metal since I see repair panels are available. On another note, I’m surprised how light the gauge is. I didn’t measure but guessing maybe 20 gauge as I could easily bend the edge around the sender access panel with my hand.

My OCD tendencies have a tough time “covering up” the rot but I am putting this one in the “preserve for future work” bucket for now. And yes, the wiring was in poor shape but I corrected that issue and we should be good to go there at least.IMG_4638.jpegIMG_4639.jpegIMG_4640.jpeg
 
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Envelope

Member
Oct 14, 2023
13
5
Arkansas
I couldn’t find an obvious source of water intrusion but the last rain was pretty light. I may need to simulate a downpour with a garden hose before it gets any colder. No obvious rust or water tracks on the perimeter behind the trim panels. I used some abrasive wheels on a drill (the red plastic 80 grit ones) to remove the loosest rust and get to bare metal where I could. Cleaned everything up with acetone and then coated with a layer of Ospho. Going to let that dry for a few days and then I’ll prime and paint. I couldn’t find any spots that were rusted through but there are several “bumps along the edges that look like rust is happening below the pan and pushing up. I figure in a few years I’ll go back and replace all the sheet metal since I see repair panels are available. On another note, I’m surprised how light the gauge is. I didn’t measure but guessing maybe 20 gauge as I could easily bend the edge around the sender access panel with my hand.

My OCD tendencies have a tough time “covering up” the rot but I am putting this one in the “preserve for future work” bucket for now. And yes, the wiring was in poor shape but I corrected that issue and we should be good to go there at least.View attachment 65562View attachment 65563View attachment 65564
I found that parking my disco on a slight incline, with the passenger side lower, helped both the sunroof leak and the back door leak.
 
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Envelope

Member
Oct 14, 2023
13
5
Arkansas
Thanks. That would track with where most of the rust is. I’m going to hold off repairs until we have a good rain to see if I can find the source. I’ll take a closer look at the seal.

I just realized that you can adjust the door lock striker to make the door seal tighter to the seal. I have adjusted the rear door about 1 mm. I have to slam the door a little harder to make it close, but hoping it will seal at the top better and not let water in when it rains.
 
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Envelope

Member
Oct 14, 2023
13
5
Arkansas
Discovery Workshop Manual - 2nd Edition - Eng

SECTION 76

The door lock striker can be adjusted by loosening the striker and moving it in the appropriate direction or by adding and removing spacing washers between the striker and ’B’ post.


Screen Shot 2023-11-20 at 8.04.59 PM.png
 
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AlWorms

Member
Feb 12, 2022
19
11
Northland, NZ
You can also fit the D2 upper door seal, that is additional to the standard door seal. I attached it with 3M body tape, rather than making holes.

None of the water sits on top of the rear seal, it's forced to run down either side.