W211 Boot water leak fixed

[SL03WLY]

Finally found where the water was leaking into the boot spare wheel well area. I changed both tail light gaskets and the rubber trims seals on either side. Still no luck. Then traced where the water goes down towards and noticed from the side trim pieces it goes along side the boot rubber seals. Also saw a gap in the panel on the left but the right side was quit a tight gap so hammered the left side down with the old dolly to match-ish. So bought a new rubber seal from dealers, rust converter and some sealant and all is well now.

So anyone else with water in boot area, consider checking the boot rubber seal for signs of rust especially in the bottom area before buying light gasket or the rubber side trims. May just require some £5 sealant to patch the area unless you are an*l. Boot is also a bit harder to close now after replacing the boot seal.




This is where majority of the water was making its way into the wheel whell

 

[oldguy57]

Good bit of detective work there amand. That is quite a gap in the panels- any explanation, such as previous impact damage?

 

[SL03WLY]

Good bit of detective work there amand. That is quite a gap in the panels- any explanation, such as previous impact damage?

Thanks! @oldguy57. In regards to the gap, I have no idea why the left was wider then the right side. Couldn't see any signs of previous damage either so am bit stumped as to why

 

[SL03WLY]

So after the last attempt at fixing water leaikng in the boot, it unfortunately did not work.

So after a few more attempts of investigation I used UV dye and found it is leaking water in from the panel gaps highlighted below.

Should've realised sooner, as there are small rust patches beneath now.

I intend to use seam sealer, after a bit of rust treatment, sanding and painting here but it still begs the question as to where its coming in from in the first place.

I took advise on another thread and applied silicone sealant in the boot rubber seal and tail light gaskets liberally. Along with some areas with silicone grease. The boot lid panel has also been re-sealed with tiger seal. All the rubber trims have been replaced too. AS in the usual suspects have been addressed as per past advice others have given.

When pouring water from the top it doesn't trickle down to the highlighted areas straight away. Giving false sense.

My worry is after applying seam sealer on this part, it may flood water on the other side of the panel, where the boot lock hinge is. As its an electronic boot release.

Anyone else faced similar before? an precautions using seam sealer?

I bought a brush on seam sealer.







Thanks

 

[SL03WLY]

So turns out it’s actually the boot rubber seal that’s letting water in. Found a part near it and squeezed the rubber seal only to see water coming through the inside of the seal.

Despite replacing it 3 years ago, I think I am going to buy new one but remove all the silicone grease and sealant and install it dry/factory way and see.

Not sure if the seal has a particular way it needs to go on. Any advice?

 

[W1ghty]

So turns out it’s actually the boot rubber seal that’s letting water in. Found a part near it and squeezed the rubber seal only to see water coming through the inside of the seal.

Despite replacing it 3 years ago, I think I am going to buy new one but remove all the silicone grease and sealant and install it dry/factory way and see.

Not sure if the seal has a particular way it needs to go on. Any advice?

On my facelift W211 it was the plastic side strips and the rear lights that caused the leak

New Boot Trim from MB Grangemouth Parts

Bit the bullet the other day and rang MB Grangemouth (Parts dept) for some new rear boot drain/trim parts . Fearing that worst , I left Euan with the job of deciphering my email pictures as to which bits I needed . He came back to me with the grand price delivered of £24 ish . The parts...

forums.mercedesclub.org.uk

 

[OneForTheRoad]

On my facelift W211 it was the plastic side strips and the rear lights that caused the leak

New Boot Trim from MB Grangemouth Parts

Bit the bullet the other day and rang MB Grangemouth (Parts dept) for some new rear boot drain/trim parts . Fearing that worst , I left Euan with the job of deciphering my email pictures as to which bits I needed . He came back to me with the grand price delivered of £24 ish . The parts...

forums.mercedesclub.org.uk

On mine it was leaking from behind the number plate holder , about 16 if not more possible leak points behind it. Maybe the 3rd brake light also .

 

[OneForTheRoad]

So turns out it’s actually the boot rubber seal that’s letting water in. Found a part near it and squeezed the rubber seal only to see water coming through the inside of the seal.

Despite replacing it 3 years ago, I think I am going to buy new one but remove all the silicone grease and sealant and install it dry/factory way and see.

Not sure if the seal has a particular way it needs to go on. Any advice?

Best to use puraflex 40 from Toolstation on the metalwork, then put the seal in place

 

[SL03WLY]

On my facelift W211 it was the plastic side strips and the rear lights that caused the leak

New Boot Trim from MB Grangemouth Parts

Bit the bullet the other day and rang MB Grangemouth (Parts dept) for some new rear boot drain/trim parts . Fearing that worst , I left Euan with the job of deciphering my email pictures as to which bits I needed . He came back to me with the grand price delivered of £24 ish . The parts...

forums.mercedesclub.org.uk

Yeah I did this too after reading your thread at the time. I've also seals the boot lid plate with tigerseal at a body shop when fitting a facelift one.

But this time I tracked the water coming in from the boot lid seal itself. When I squeezed it water was coming through. There is also rust patches all round now. Will tackle this and see how it goes. But appreciate everyones help and input. May need to revisit the other areas if it doesnt resolve

 

[oldguy57]

Yeah I did this too after reading your thread at the time. I've also seals the boot lid plate with tigerseal at a body shop when fitting a facelift one.

But this time I tracked the water coming in from the boot lid seal itself. When I squeezed it water was coming through. There is also rust patches all round now. Will tackle this and see how it goes. But appreciate everyones help and input. May need to revisit the other areas if it doesnt resolve

As a general point if you use silicone sealant make sure it's not an acid based one because it can cause metal corrosion when water gets at it. Also I've found that smoke testing in a boot is the best way of locating the exact point of leaks. Made my own from a cheap pond smoker a couple of computer fans and water in a plastic tub (total about a tenner) but you can hire a smoker. It's never failed to identify leaks in boots.

 

[OneForTheRoad]

As a general point if you use silicone sealant make sure it's not an acid based one because it can cause metal corrosion when water gets at it. Also I've found that smoke testing in a boot is the best way of locating the exact point of leaks. Made my own from a cheap pond smoker a couple of computer fans and water in a plastic tub (total about a tenner) but you can hire a smoker. It's never failed to identify leaks in boots.

Blue Peter fan then ?