124 wagon sunroof drains - PeachParts Mercedes-Benz Forum

Maxbumpo · #1 05-26-2015, 10:49 AM

Has anyone found rear drains at the rear of the sunroof on a 124 wagon (or sedan, they probably are the same)? If they exist, how can I access them to make sure they are not clogged?

I've got water entry on the passenger side. I know that the sunroof seal needs to be replace (about $116 is the best price I can get from MB), but I'd like to make sure there isn't another problem or two problems before I start throwing $$ at it.

Austin85 · #2 05-26-2015, 11:40 AM

I have a post on this for my 300sd.

Find drains. Open sunroof. Get a small plastic bottle and a few ounces of water. Gently pour like 3-4 oz along the back end of the left side track of the open sunroof. - Note where it exits. Will either be somewhere inside or outside of your wagon.

Do the same things for the right side track. Hopefully one of the tracks exits the water outside of your car so you can locate the exit drains.

....

Austin85 · #3 05-26-2015, 11:49 AM

Edit. That's for the rear drains.

There are 2 front also and you can do the same for the front corners.
You should be able to visually see the 2 front drain openings from the top of the open sunroof. You can clear these out first with a compressed air hose.

If your rears are clear and it's just a front clog then you are lucky.

Maxbumpo · #4 05-26-2015, 02:01 PM

Austin, thanks, that is worth a try. I've done the same test on the front drains, neither was clogged and both drain just fine. I also ran a piece of weed-wacker cord down each front drain, after melting the end into a ball.

If your test works, driver's side should result in water draining outside the car, B or C pillar, while passenger side is leaking inside the car.

I sure do hope this is simply a clogged drain and not rust-through.

Austin85 · #5 05-26-2015, 02:35 PM

After you clear the drain you still need to gently pour water in to the tracks to make sure it was just a clog, and not rusted through.

If it was rust through then you will still get water in the cabin. If not then you may be OK. The only way to really know if your drain track area is not rusted is to remove the headliner area around the tracks and visually inspect the drain tracks. This is what I did yesterday on my SD.

I am now in the fun process of patching and repairing a 3-4" gap on the rear right corner of the drain track. ( it is not really a pan. ) You can see my pictures in my post today.

Maxbumpo · #6 05-26-2015, 02:44 PM

Austin,

Saw your post and pix, that looks like a tough job. Have you considered replacing the entire sunroof frame?

Finally took the time to dig into the EPC, and indeed there are two drains in the back. This diagram from the EPC clearly shows a back drain nipple on the near side.

I will have to get at those rear drains somehow...

Austin85 · #7 05-26-2015, 02:53 PM

I once removed a sunroof and put it back together. There are sunroof repair shops who won't do Mercedes sunroofs. I know why. I am going to try to patch it.

Here is a pic I found that shows a track that got rusted so you know what would be happening and what it would look like.

Maxbumpo · #8 05-28-2015, 08:55 AM

Rear drains go down the C-pillar, then over the top of the rear wheel hump, down and out so they exit the body behind the rear wheels under the rear bumper wrap-around on the side of the car.

If you remove the two nuts and washer behind the spare wheel (driver's side) and behind the jack (passenger side) then the bumper wrap-around portion is loose enough that you can pull it away from the body slightly and see the black rubber tube exiting the body.

I ran an old speedometer cable through both of them, did indeed get some discharge from the passenger side like it was plugged or partially plugged. Buttoned everything up, sprayed the top of the car with a hose for ten minutes, and no more water inside the car.

Maxbumpo · #9 05-28-2015, 08:58 AM

In addition, one can see the connection at the sunroof pan by:

- Removing the grab handle above the rear door
- Pull away the door seal
- Pull down the black plastic "U" channel which attaches the headliner to the door frame (about a 2-foot long channel).
- Gently pull down the headliner at the rear corner of the door, and you can shine a light inside to see the corner of the pan and the attached black rubber hose.

Maxbumpo · #10 05-28-2015, 10:30 AM

Here are some shots of the drain tube attached to the rear corner of the sunroof pan, the headliner area that you can pull down (red arrow is pointing to black channel that you can pull down off the door frame), and the exit at the rear bumper and behind where the jack is stored.

dude99 · #11 05-28-2015, 10:42 AM

Excellent, thanks for the pictures

vstech · #12 05-28-2015, 11:40 AM

I would NOT recommend using compressed air to clear the drains... the hose connected to the pan is thin and rubber... air pressure could easily pop them off... use a trimmer line, or thin drain snake...

Maxbumpo · #13 05-28-2015, 12:22 PM

Quote:

Originally Posted by vstech

I would NOT recommend using compressed air to clear the drains... the hose connected to the pan is thin and rubber... air pressure could easily pop them off... use a trimmer line, or thin drain snake...

Agreed, I've never liked that idea.

Austin85 · #14 05-28-2015, 11:29 PM

Glad you got the tubes unclogged. I found a roll of 10 gauge soft insulated wire in my garage and used this for cleaning out the tubes. Nice thing is you can pick up as long of a piece at HD for a few bucks.

..

jbach36 · #15 05-28-2015, 11:47 PM

You can use transmission fluid or the power steering fluid that rejuvenates rubber on your seal, rather than buying a new one. Depending on the condition of your seal, you might not even have to take it out. Just brush the liquid on there as best you can and let it soak in.

I had just one corner that was getting hard and causing a problem, but my power steering fluid fixed it.