I've learned the hard way that keeping sunroof drains clear is critical for cars especially in our Pacific NW region climate. I’ve had Rovers and other vehicles that develop roof drainage issues -- not “if”, but “when" esp for the vehicles I park outside under the trees. The 2020 Defender’s been out in the wild about 3 years now from new, and I'm certain the dealer did not clean any drains out at my 20K oil change last year. So it’s time.

Today I spent a few hours figuring out water management for the pano roof drains and a method to access/clean the drain channels and holes. Good news is that my drains still drained after testing. But I’m glad I got in there as there was gook, gunk, debris, pine needles and decayed debris that was turning to dirt — waiting to clog my drains up. I now have peace of mind and will add to my annual "list".

I could not find any "how to" on this online, so here goes...

The key is -- to access the drain channel, remove the long piece of press-fit painted trim on either side of the sunroof. It's the long slender piece of painted trim with a rubber edge, running lengthwise on the car, between the movable/fixed glass roof panels and the roof rails.

Below should be applicable for the glass pano roof cars, 90/110 & probably 130. The canvas roof ones are likely different.

The basics (see diagram):

• Defenders have 4 drain tubes, 1 each corner of the pano roof. A slender plastic channel runs the length of the sunroof/glass roof aperture and the drains are at either end.
• Per the service manual, each of the front drain tubes splits into a Y and has 2 connections up front. 6 drain locations total. Confusing but see diagram below. See the little "x6" indicating 6 drain points.
• Up front, I located and cleaned out the front 2 primary drains, but not the secondary drains. I think these secondary drains are under pieces of the sunroof frame and not accessible from above? Unsure. More on that later.
• At the rear, drain exit points are at the rear of the roof glass panels... I thought they'd be at the end of the sliding panel. In fact they're all the way rear at the corners of the fixed glass panel.

My Process:

1. LOWER CAR - I lowered mine to the bump stops with my GapIIDTool for best access. Step stool on side of car.
2. REMOVE TRIM STRIPS - With sunroof CLOSED, I carefully removed the two long slender painted trim pieces that are on either side of the pano roof. These are between the sunroof glass panels and the roof rails. Note that this was made slightly annoying by my expedition roof rack but this is all possible with the rack on. To remove these painted trim panels, pry up carefully at the front most portion. I’d recommend using your hands, not pry tools once you get it loose. Can you imagine cracking your sunroof glass by prying against it. Anyway — slowly work your way back. It will slowly come unclipped. This piece is about 4-5 feet long. I set it aside and cleaned the underside/rubber trims.
3. OPEN SUNROOF - Now you will want to OPEN the sunroof panel fully. This gives you better access to the water channel that runs the length of the glass area (movable panel and stationary panel)
4. LOCATE FRONT PRIMARY DRAIN HOLE - What you will see is a drain hole (it's a rectangular area with a round hole in bottom) up front, and a channel in the plastic that continues rearward.
5. LOCATE REAR DRAIN AREA AT END OF CHANNEL - The rear drain hole is at the very end of the plastic channel.
6. CLEAN - Clean this water channel. Very well. Get every bit of gook and debris out of it. I went through 5-6 microfiber towels, using a plastic trim tool with a bent end with the microfiber wrapped around it. I used a little Simple Green motorcycle/aircraft cleaner (I like this over regular simple green as it doesn’t screw up rubber or plastic or painted surfaces) to help clean. I used the squirt bottle on the Simple Green Bottle to aim it into the plastic water channel. The bubbles in it helped me see things and clean it.
7. CLEAN AGAIN - Then I got even more surgical and went through probably 100 Q-tips. Until no more dirt came off on the white tips. I found the q-tips were able to be bent, and get in the areas I couldn’t quite reach. If I didn’t have the expedition rack I think this would be easier.
8. TEST WITH WATER - I used a little syringe (well a big one) and a wine bottle to dump water in carefully at all 4 corners to verify that drains worked.
9. ALSO CLEAN UNDER THE FRONT SEAL THAT RUNS ACROSS THE FRONT OF THE SUNROOF - Then after cleaning, I lifted up the front rubber seal and found a good amount of junk under each corner of it as well. I pulled it up 5-6 inches on either side, and didn't remove the entire piece of rubber. Didn't want to cause issues.

Where do the drains come out?

• The front drain tubes drain just behind each of the front wheel. Somewhere over and behind the mudflaps area (if you don't have mudflaps just imagine where they'd be). So after pouring water in carefully into the drain area, this is where you will see it drip out. I could not and did not try to find the actual termination point of each drain tube, but it poured out on the ground. I think I'd have to get under the car, and in the front remove the wheel arch trims perhaps to find the exit point.
• Rear drain tubes drain are about 1 foot inboard of the rear corners, in front of the rear bumper area. More on the back of the car than the side of the car, which was surprising. Again, I didn't get under the bumper to see exactly where, as I was satisfied with the stream of water coming out.

UNANSWERED QUESTIONS: This is a work in progress. Few things still to figure out. Hoping others here can help or I'll iterate and revise this 'how to'.

• Where is the secondary connection for each of the front drain tubes?At some point I’ll drop the headliner and have a go at it from the bottom. I think it's slightly forward of the primary drains I located and cleaned out - but not accessible from the top.
• Where the rear drain hole is. I can see it draining, but I cannot see the little hole like I see up front. Perhaps I'm blind, and it was getting late in the day
• Where exactly the exit points are on the underside of the car? Thinking that in future clogs at those ends may need to be addressed -- also I fondly remember the rubber one way valves that could clog on LR3/LR4/RRS.
• If any of you follow the rather horrific issues with drain tubes on L405 / L494 Range Rovers, the metal drain tube spigots that are part of the lower sunroof frame rust out and are causing great havoc. Google search will be quite enlightening and depressing. At some point I want to pull the L663 headlining to confirm that JLR redesigned the L663 to be different from L405/L494. Hopefully so. I think based on my research today they are indeed a completely different design on L663 - which is great if proven correct.

Hope it helps!


The top side of the trim strip you'll be removing


The underside of the trim strip - quite easy to see how it fits into the clips (press fit)


FRONT PRIMARY DRAIN HOLE: Using a pointer to indicate where the front primary drain hole is.


DRAIN CHANNEL: Using a pointer to show the drain channel. This is drivers side of car. That silver metal clip is what holds the trim strip down.


REAR DRAIN HOLE: This is the rear most portion of the drainage channel - the pointer shows where the drain hole goes down (right at the end of the channel).


REAR DRAIN HOLE / ALT: The rear drain hole location.

This is a shot taken from the front of the car looking towards rear.. you can see the primary drain hole in foreground and the long (already cleaned) drain channel


Looking down in the front primary drain from above. Stuck some weed trimmer line down the hole so you can see location.


Cleaning 'action shot' - first I cleaned with microfiber and plastic safe APC -- and whatever else I could shove in there to get the debris out. Then I used q-tips and detailed up and down the entire channel.


This crud was removed from my passenger drain channel


When you are done cleaning the drain channels - also look under the front corners - under the rubber weatherstrip - it just pulls up. All sorts of gook under there. I believe this is important as it is likely where the secondary drain holes up front are -- somewhere under there.


Using a q-tip - a tight squeeze getting in the channel at points. PS don't lose your q-tips in there... they will clog a drain faster than any debris.

 

Thank you for posting this. I'm sure our 2021 is packed with pine needles as my wife's assigned parking spot at work is under a pine tree.

 

There was a recent article on "The Drive" about this, but on Porsche. Apparently they clog then the next path for the water is the floor. Which fills up and shorts out the module for the door keys, so the car will not open or if you get it open will not start. It also kills some other obscenely expensive modules as well. So the repair ends up cost in the tens of thousands of dollars. So not really a bad idea, considering how much of the electrical system is in the Defender's floor. Funny how 40 years later, the Porsche still has the same problem. My 911 did this as well. There was nothing in the floor to short out, but it was really uncomfortable. Ended up drilling a couple of drain holes in the floor. There was no fixing the leaks, they where "Engineered Leaks."

 

Thanks for posting this. As a fellow PNW'er (PDX), I'll need this at some point.

Cheers

 

This is a great post, thank you for all the details and the photos. Extremely helpful!

I am sure my 2020 needs to be cleaned out, next warm weekend I am going to tackle this.

 

A shout-out to the original poster—I followed his process and cleaned the drains on my 110S this morning. It took maybe 30 minutes and was well worth the effort. I didn't have much in the areas of concern, but there was enough dirt to warrant a good cleaning to ensure it didn't muck up. It's an important thing to do. I had a Volvo XC60 that was bone dry one night and, by the next morning, had several inches of water on the passenger side. When the drains back up, it overflows really quickly. So, make this an annual maintenance piece.

 

Thrilled it helped someone out. I live in a constant state of fear of clogged sunroof drains here in Oregon.

 

I don't know if I trust myself to do this... I don't mind taking things apart, but I just feel like I might break something on this. I keep my car in my garage, but it does sit outside every day when I'm at the office. I'm not super worried about a ton of gunk in the drains, as the climate of the PNW is vastly different to Ohio. I will have my dealer check it next time I go in for an oil change just to be sure, though!

 

Does regular daily auto car wash help this problem?

 

This is another reason to not have a glass sunroof on an off road truck..