How to Repair
You may be able to carry out some of the repairs without removing the headlining; but if you’re going to go the whole hog, you may as well take it out! This isn’t difficult; you just need the time and perseverance with removing lots of fixtures and fittings (and working out how it comes apart). Most roof linings should have some give and shouldn't break or kink too easily. You can also try to loosen part of it to gain access, e.g. one side, the front or back?
- Tools: The usual screwdrivers, small spanners sockets etc, torx allen keys or sockets.
- Materials: Clean cloths, mastic/sealant, Araldite.
- Refer to your vehicle manual.
- Remove the headlining (feel free to try and carry out a repair without removing it, but it may be a struggle).
- Release the drain tube pipes (beware, the tubes can break off!)
- Release the sun roof motor connectors and earth connection (if fitted).
- Undo any screws that holds the motor to the sunroof drive (if fitted)
- Undo the screws holding the ‘drip tray’ to the sunroof frame.
- Lower the drip tray.
- The sunroof can then be removed, (there is no need to remove the glass).
- Clean the roof edge and sun roof mating surfaces to provide a good bond and seal.
- Apply a good quality sealant or vehicle mastic. Use good quality, or you may be back again later! (E.g. The good quality silicone normally contains a higher percentage of silicone and less 'filler' material).
- Replacement is the reverse procedure.
- Check for correct fitment and position as you go.
- Do not over tighten the screws; let the sealant do its job.
- Check the drain tube fixing points whilst your there (even if they don’t leak, or you could be back again later!) - See 2. Drain Tube Fixing points.
Note:- The rear edge of the sunroof may have to be lifted first to clear the hole
Drain Tube Fixing points.
Note: Araldite is very good for re-sealing and provides for a more rigid fixing, (beware; the drain tubes can break off if you try to remove the pipes! Araldite can also be used to fix these!).
- Ensure the repair area is dry and clean.
- Clean the area around the plastic to metal joint to provide a good key for the glue. You can roughen it up with some sand paper. (Remove any old excess mastic that will prevent the glue from providing good adhesion).
- Apply the Araldite ensuring the joint is well covered. Apply a second layer of glue if needed.
- Allow glue to dry thoroughly before testing for leaks.
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.
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.
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?)