w123 300TD rear water leak - PeachParts Mercedes-Benz Forum

240dddd · #1 12-19-2017, 03:22 AM

When it rains my '81 300TD is getting wet around passenger side rear corner, in front of the access door for the first aid kit and rear window washer fluid. I pulled the back panel off of the rear door but it surprisingly it does not appear to be leaking inside the door itself.

It could be the rear hatch seal and door are not sealing correctly, but I've spent some time adjusting the door to make sure it is closing tight. I don't see evidence of it leaking around the seal, but that doesn't mean it isn't the problem.

There is also water pooling in the well underneath the window washer fluid container.

My question is whether any 300TD owners have any advice about tracking down rear hatch area leaks?

moon161 · #2 12-19-2017, 08:06 AM

Look for wear in the gasket. I have a leak in the top portion of mine, right in the middle.

vonsmog · #3 12-19-2017, 08:41 AM

Only rust I had on my 85' TD was on the pass side fixed window under the seal, let water in and it sat inside the well like you are getting. rusted a small hole in there as well. Welded in all new metal and all is good now. When I put the windows back in I used sealer to make sure no water was going to come back in.

Maxbumpo · #4 12-19-2017, 10:02 AM

Check the outside trailing corner of the right rear wheel well for rust through. Tire will throw water against that seam and it gets inside.

Another possibility is that the rear tail light seal is no longer sealing.

vstech · #5 12-19-2017, 10:30 AM

...

Mine all had rust in the window channel in the rear side windows.

The windows come out very easy, just unscrew the molding and push out the window.

vstech · #6 12-19-2017, 10:40 AM

Also, the sunroof drains in the upper vent by the side windows, if it trusts out, sunroof could be draining into a hole...

Also, the sunroof drain tubing over headliner could be leaking...

funola · #7 12-19-2017, 11:03 AM

81 300TD is a wagon. Where is the first aid kit located in a wagon?

BirthdayBenz · #8 12-20-2017, 04:15 PM

First Aid Kit is located behind the Passenger side access panel in the cargo area.

240dddd · #9 02-12-2018, 05:05 PM

I think it might be the right rear tail light. It is chipped in the lower inside corner and the seal looks to be shrunken, possibly ripped.

Does anyone still make these seals? I've been looking and haven't found any, but am not sure if I'm using the right nomenclature when looking for them.

Ndralle · #10 03-10-2019, 07:42 PM

Old thread but my guess is dried out seam sealer in lift gate hinge pocket.

240dddd · #11 10-18-2020, 07:05 PM

Old thread but I still haven't solved this problem completely. I did use some butyl type tape to seal around the rear windshield washer which solved part of the problem. I also used some around the rear taillights but that didn't help.

I found that if I pour water at the top of the hatch water starts dribbling out the passenger side D-Pillar near the top of the pillar. Upon closer inspection it looks like it is coming out from under the seal which would likely mean that water is getting under the seal near the top.

I pulled the seal out a bit along the D-Pillar and there is a bunch of old adhesive piled up under the seal but seemingly not attached to the seal, i.e. the seal is just sitting on top of the bumpy old adhesive which is probably keeping the seal from doing its job.

I think this would mean a previous owner either replaced the old seal and used crappy adhesive, or never cleaned out the original adhesive and just set a new seal on top of it (i haven't been able to discern if MB used adhesive on the original seal or not). My plan is to clean off the old adhesive down to painted metal and re-install the seal.

My question is, once i have the old adhesive removed should I be using adhesive when reinstalling the seal? Or should it do its job just sitting in the groove?

240dddd · #12 10-01-2021, 04:44 PM

Resurrecting an old thread yet again. Last spring I cleaned out the hatch seal, re-glued it in some parts and fixed some small tears. I tested it with a hose extensively, and between that and spring/summer rains I was not getting any dampness in rear.

Well, we had our first heavy fall rain here in Seattle this week and the passenger side rear is getting really wet again. If I sit in the car during the rain I don't see any dripping down from the hatch opening, nor do I see any in the wheel well or coming out around the window seal.

Don't really have a question here. Just venting.

vwnate1 · #13 10-01-2021, 06:54 PM

I feel your pain .

Luckily my greymarket 300TD parks in a garage and almost no rain here in Los Angeles so no leaks yet

.

I wonder of the overflow drain tube in side the fuel filler pocket might be cracked or not properly connected .

My '82 240D had this issue and it wasn't until I took the fuel tank out I discovered the drain hose wasn't properly fitted leading to right side rear well puddles .

Try pouring water in the fuel filler pocket, the filler neck also has a very soft rubber grommet that allows water to dribble in .

I used *one* URO brand grommet, the Diesel fuel turned it to goo in short order so I bought one from the M-B Classic Center, problem solved .

URO Parts Support · #14 10-04-2021, 01:32 PM

Hi Nate, are you talking about this item? Filler Neck Seal 123 997 35 81

That's not an item that we offer, but the MTC brand seal is (allegedly) said to slowly melt after contact with fuel.

Shern · #15 10-04-2021, 04:11 PM

Quote:

Originally Posted by URO Parts Support

Hi Nate, are you talking about this item? Filler Neck Seal 123 997 35 81

That's not a item we offer, but the MTC brand seal is (allegedly) said to slowly melt after contact with fuel.

I’ve used this seal… It lasted about a month.