Leaking Boot...
#1
Racer
Thread Starter
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
...or Trunk (I think
)
How can I check the seal? The previous owner said it had been replaced, it leaks into the box that the sunroof motor is in above the front seats. 1991 S4 Auto...
![Confused](https://rennlist.com/forums/images/smilies/confused.gif)
How can I check the seal? The previous owner said it had been replaced, it leaks into the box that the sunroof motor is in above the front seats. 1991 S4 Auto...
#2
Rennlist Member
Join Date: Feb 2008
Location: Lillington, NC
Posts: 2,742
Likes: 0
Received 0 Likes
on
0 Posts
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I think the sunroof track is supposed to have a drain hole on each side. The hatch hinges are supposed to be sealed also, so it may be leaking through there also.
#3
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Remember changing your spark plugs? How you used dielectric grease on the ceramic of the plugs?
Same thing here. That dielectric grease keeps water out. So open your rear hatch and clean out that whole area, then simply coat all of the rubber seal under the hatch with your dielectric grease.
Next, open your sunroof and coat the front metal edge (and sides for whatever area that you can reach) with more dielectric grease.
Close your sunroof. Close your hatch.
Now spray your car with water and check for leaks.
What you've done is given your old seals some new life with the above...so if a *seal* was your problem, then the dielectric grease will give you a couple of months of time for going leak free. Of course, if you have a leak due to a crack/puncture or debris somewhere, then the dielectric grease just tells you that you have a bigger leak issue than just an old rubber seal.
Easy test, though...and almost free. Use Vaseline if you don't have dielectrc grease handy. Generally the same stuff.
Same thing here. That dielectric grease keeps water out. So open your rear hatch and clean out that whole area, then simply coat all of the rubber seal under the hatch with your dielectric grease.
Next, open your sunroof and coat the front metal edge (and sides for whatever area that you can reach) with more dielectric grease.
Close your sunroof. Close your hatch.
Now spray your car with water and check for leaks.
What you've done is given your old seals some new life with the above...so if a *seal* was your problem, then the dielectric grease will give you a couple of months of time for going leak free. Of course, if you have a leak due to a crack/puncture or debris somewhere, then the dielectric grease just tells you that you have a bigger leak issue than just an old rubber seal.
Easy test, though...and almost free. Use Vaseline if you don't have dielectrc grease handy. Generally the same stuff.
#4
Addict
Rennlist Member
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
Could be from the locations mentioned. First, there are 4 drain holes for the sunroof compartment. They are located in each corner. If you want to make sure they are draining properly, use a length of thick weed whacker line. Run the line through each hole to make sure they are not clogged. The rear holes drain into the hatch tracks and the front drains through the A pillars down into the back of the front fenders. That's probably not your issue, but it's always a good idea to make sure they drain.
If the hatch weather stripping has been replaced, I would bet that they didn't "SEAT" the weather strip properly at the top between the hatch hinges. I say this because it's not an easy task to do when replacing it. I used a large flat head screw driver with a thin block of wood to make the weather strip seat correctly. I basically pried the screw driver against the block to push the seal down over the metal lip.
If that is not your issue, pull the rectangular plugs at the back of the headliner bordering the sunroof motor cover and look to see if either side shows water leakage. It should be apparent, but you can always recreate the leak with a garden hose when all is closed up.
Other than those 3 things, there really isn't any other way to my knowledge for water to penetrate this location. Good luck!
If the hatch weather stripping has been replaced, I would bet that they didn't "SEAT" the weather strip properly at the top between the hatch hinges. I say this because it's not an easy task to do when replacing it. I used a large flat head screw driver with a thin block of wood to make the weather strip seat correctly. I basically pried the screw driver against the block to push the seal down over the metal lip.
If that is not your issue, pull the rectangular plugs at the back of the headliner bordering the sunroof motor cover and look to see if either side shows water leakage. It should be apparent, but you can always recreate the leak with a garden hose when all is closed up.
Other than those 3 things, there really isn't any other way to my knowledge for water to penetrate this location. Good luck!
#5
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I found that it is easier to check where the leak is coming from at night, using a flash light. The light reflects of the water. I found my hatch seal leaks at the top corners, the water drips from there on the roof liner and from there in my case it goes behind the quarter panels and follows the inside hatch liner to the rear of the hatch. mrmerlin suggests using DOW Corning 111 on the inside of the seal - here it is sold under the Molykote brand (Molykote 111 or Molykote silicone compound 111).
#6
Rennlist Member
![Default](https://rennlist.com/forums/images/icons/icon1.gif)
I found that it is easier to check where the leak is coming from at night, using a flash light. The light reflects of the water. I found my hatch seal leaks at the top corners, the water drips from there on the roof liner and from there in my case it goes behind the quarter panels and follows the inside hatch liner to the rear of the hatch. mrmerlin suggests using DOW Corning 111 on the inside of the seal - here it is sold under the Molykote brand (Molykote 111 or Molykote silicone compound 111).
![Big Grin](https://rennlist.com/forums/images/smilies/biggrin.gif)