How to Repair
2.1 Drain Tubes.
There are only two drain tubes fitted to each sunroof. These are all towards the front and operate to some extent independently. The rear sun roof drain tubes exit near the rear lights and on the front they disappear down the ‘A’ posts by the windscreen. (On the Land Rover Discovery)
You need to ensure:
- The tubes aren’t blocked (you can pour water into the sun roof gully and watch it run out on the ground).
- The route the tubes have been run is not higher than the drain tube fixing point itself.
- That the tube from the fixing point isn’t broken, as they can be brittle.
3. Rubber Seal.
This is an easy item to change if you can get hold of one. It appears only to be sold as part of the sunroof assembly? However, I have seen them for sale separately on e-Bay.
But before you go down this route and spend hard earned cash; is it the seal causing the problem? It should only be the cause of the problem if it is dirty, damaged, or has an inherent defect? This should normally be visible.
The root cause of water ingress in a sun roof is often via:
- Item 1. The sunroof to roof external seal.
- Item 2. (Once the water is in) the drain tube fixing points and any problems with the drain tubes.
To remove the seal, simply open the sun roof and pull it out of the recess.
- Check for damage and cleanliness.
- Check the sealing rubber compression (you can check this by watching the rubber compress as the roof closes).
Note that you may see water on the seals from condensation running off the glass sun roof, or water running in from outside when the window opens.
Testing
You can test for leaks by pouring water into the drainage ‘drip trays’ and watching for water running out under the car. Note that:
- The drainage holes from the sun roof may be at one end (on the Discovery it's towards the front of the car) and operate to some extent independently on each side. The vehicle will need to be on the flat or facing up or downhill.
- This does not check the sunroof to roof external seal.
To check the overall water integrity of the car (for the sunroof), you may need to leave the car parked in the rain for a day. Note that the most efficient way of testing is to park the vehicle on a slight slope. You may need to try both nose up or down? (Take note if your vehicle tends to leak more when parked in a particular position?).