I'd suggest taking the pan completely off to properly seal the sunroof flange to the roof.

 

(re: above -- silicone can work great too if that's what you have, I just have always heard in my old geezer Porsche crew that silicone is for the layman, not the pros ie... use seam sealers the manufacturers use/urethane instead of silicone. Nothing really scientific about that although some say the gassing off of silicone can cause rusty metal down the road. PS In my other car life I have a few old Porsches I've restored and silicone is a no no in that world)

Anyway, check this out. Explains it all really well!

 

Sorry I was not clear earlier. I used silicon to re-attach those plastic corners shown in your picture. I removed both corners and cleaned completely. Silicon is good for this because you do not want anything thick as it will raise the corners above the tray and will hold more standing water in the tray.

I used pure butyl tape for the to seal the roof assembly flange to the roof.

I did have a little worry about the butyl flowing out in hot temperatures, but it has been fine for many years. Of course I live in a temperate environment and my truck is white.

 

3M Marine Adhesive Sealant 5200

https://www.amazon.com/gp/product/B001R0GUZG/ref=ppx_yo_dt_b_search_asin_title?ie=UTF8&psc=1

 

if you’ve already sealed the top sunroof flange, unbolt the tray and remove the corners on a work table. I used a combination of a small hot (heat gun) putty knife to cut through the old caulk between the inside of the tray and the corners. Once you’ve cut through most of that, use the heat gun on the corner from the inside of the tray as you put pressure up on the corner from the bottom of the corner outside the tray. Obviously don’t overheat the plastic, a little fiddling and it will pop out. Clean up the old adhesive from the tray and the corner. Use what like to reset it. I used JB weld for the corners. They should snap into the frame nicely when you put them back

 

yes when I did mine I filled in the gap to stop the water coming out

 

I got it all sealed back up with 3M 5200 so it's good to go. While I had the interior out I removed the stock navigation antenna and replaced it with a sharkfin one off a salvaged Cadillac. Now I have a real OEM looking XM antenna. Also OnStar if I want it in the future..lol.

 

great idea on the antenna, also good time to add a backup cam, wire for future lighting and dynamat or similar.

 

Thanks for the photos of the sunroof drain issue. I have a 2001 Disco 2 having the same issue. Quick question on the corner pieces did you just remove them and reseal or replace them. I see you cut them out but wasn't sure if they were replaced or just reused.

 

Reused the corners on mine, the corners are plastic and snap into the steel sunroof tray. As far as I know you can’t buy genuine corners without buying the entire tray. I have seen a custom metal set being sold, I think on eBay. If yours are intact just get them out carefully, clean all the old adhesive off both surfaces and reattach with sealant.
Also check carefully the ****** nipple isn’t cracked. 2 of mine looked fine but when I wet tested it, they both had a small crack at the base. I sealed it with JB weld.
If you are pulling the trays check that the seal on frame to roof connection. one of mine pushed straight out, the seal had completely failed, the other released with very light pressure. I rest them with silicone once the trays were cleaned, sealed and ready to re-attach.

here’s a link that helped me in planning the job of a complete re-seal.

https://do-it-up.com/vehicles/body-e...f-Roof-Seal-01

one tip for sealing the top flange to the roof is to tape off the current location of the flange, there is a small amount play between the flange and the roof cutout. Also if you mask the frame before you install it you can let the sealant squeeze out without getting all over the roof or the sunroof frame, then take a finger and press along the seam around the frame removing the excess sealant, then remove the tape carefully and you’ll have a perfectly clean sealed connection.