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Major leak coming into drivers side floorboard

Started by jtwoods4, 01 October 2012, 02:29 PM

jbrasile

MT is absolutely right.

In fact I think they drilled a hole in my car for the water to drain when I had the repair done, this was a design oversight from MB, the hole should have been there all along.

Still, the best way to check is from under the dash with a flashlight and all paneling/carpet/insulation removed.

By the way, you MUST remove the floor insulation in order to get it completely dry, otherwise the floor will rust from the inside. Getting it out is a painful and time consuming effort because there is an air duct in the way, it is possible to take the duct out without removing the center console but it is not easy...



Tks,

Joe

jtwoods4

Can you take a picture of where the hole is drilled I'm going to do the same thing
1980 300SD

jbrasile

I will check if they really put the hole in and post a picture.

Tks,

Joe

gavin116

I had a similar problem too.  Surprisingly the same side as your car, but in my case, it's RHD, so the issue wasn't hidden by the fusebox.  However it was happening unnoticed, and it was only when the new sunroof seals and whatnot were being leak tested that water was seen ingressing into the passenger side foot well.  There are a few picture of the repair too, however they did not drill the hole that Joe speaks of.  When I see his pictures, I may take it up with the guys at the Mercedes specialist shop that done the work.  (R107 have a similar design flaw, but I think their leak is typically behind the console area.)

Quote from: gavin116 on 21 July 2012, 10:24 AM
Just fetched the Benz back from having some repair works doing

Just fetched the Benz back from having some repair works doing. 

So, the job at hand was to drop the sunroof tray and do some rust repairs. I was becoming more and more aware that there was something untoward, as I was getting a wet bum every time I drove the car when it was stood in the rain.  Indeed I could see water tracking along the hood lining, dripping onto the driver's seat.

In late April, a phone call to John Haynes ascertained what the job entailed and the likely parts needed.  The car was booked in for the end of June, and soon it became time to drop her off.

I bought a new front sunroof seal, I still had the new rear from a while back.  Added to this I bought new front and rear screen rubbers as the front screen had to be removed to remove the sunroof tray with ease and to reduce the possibility of damage to the interior parts of the vehicle.

When I dropped the car off, we took a walk round, in addition to moving the electric aerial from the right side rear flank to the left rear flank that we had agreed on doing earlier, there were a few other items they picked up on.  This included sticking down the boot (trunk) seal, and also looking at the steering box, as I have always had to continually correct the steering due to play in the system.

Some other issues were discussed including the rough idle, the fact that someone had a go at the warm-up regulator already, driving the unit down with a punch to try improve the running.  I opted to leave this for the time being, my most urgent issue was to get the car watertight again.

I will take up the issue or rebuilding or replacing both the auxiliary air value and the warm-up regulator at the same time to see if I can get the car to idle smoothly and not to run at such high RPM when stationary.  If I lower the idle speed with the nylon screw to 650, then she shakes violently, so I have to have the idle speed about 850/900 RPM, which equates to about 1200 when cold: dangerous when trying to maneuver the car out of a parking space.  These RPM'S even higher when she is in 'P' or 'N'!

Back to the topic...

Out with the front windscreen to make matters easier for the removal of the sunroof.  The body-shop cut the window gasket informing me they usually do it this way as a matter of course to prevent placing undue strain on the screen. 

This suited me fine as not only did I have a small chip on my windscreen, but I had already decided to change the 33 year old seal as a matter of course.  And well it worked too!  The screen remained intact, the chrome surround was inserted prior to placement, and everything married well upon installation.

The front screen out

The sunroof tray removed

Upon removal rust was found to be present on both the front drainage channels.  In addition, the sunroof drain on the front right side had perished and split.

Rust on the RHS sunroof drainage channel

Rust on the LHS sunroof drainage channel

The rust was removed and newly fabricated repair pieces welded in place.  These were then smoothed and painted.

Sunroof tray repairs

The sunroof was then repatriated with the car, including replacing the sunroof drains that cost me an arm and a leg...  A new head lining was installed at the same time.  All-in-all a pleasing result.  The wind deflector now pops up as it should.  The sunroof has also been adjusted to sit nice and level.

New head lining

And then there was the nasty: Ye old leak test.  On with the hosepipe, and the sunroof (prior to installing the new head lining) was dry as a bone, the front window gasket good too, but sadly water ingress into the cabin on the left.  This came as both a surprise and a shock.

Nevertheless, the extent of the rust was not too large, but it had caused water to pool in the left front passenger foot well.  I am not sure how they removed the foam pad, as you can see it is very neatly done (and neatly replaced too! after drying out).  The footwell thankfully has no major rust, there was a little surface rust, but the majority of the rust seen in the picture is from removal of the rust in the upper bulkhead section dropping into the car.

The rust and water issues on the internal left front bulkhead

The area was cut out and cleaned.  A new piece of sheet metal fabricated and welded into place.  Some sealer applied, it was etched and primed, whereafter it was painted.

Finished repair on the inside left bulkhead


The upper bulkhead section in the wheel well also received a new under seal although not shown here, it has been painted in body colour too.

The upper bulkhead section in the wheel well

Alas, the aerial relocation was also not to go smooth.  The old hole was sealed etc. and painted, a new hole was drilled in the opposite left rear flank.  The aerial was mounted and connected up using the correct 4 pin Mercedes Benz plug, and it functioned well.  Then, Ye old leak test...

Again water ingress was found in the boot, but lucky this time it was from the left tail light cluster.  This was removed, and it was reseated using a sealing compound, and reinstalled.  No more leaks!  I will have them replace the right side, as I found it nearly impossible to marry the frame to the seal to the lens.  That is why I didn't even try do the replacement seal on the right.

The trip back up to storage went smoothly, the steering is wonderful now, I don't have to constantly correct the direction.  Nice to have the use of the sunroof, now if only the air-con...

So, what next? 

I shall see, but I think I will probably try pulling the left front door card, dismantle it, and replace the sponge wadding to make the material less saggy.  I also want to do an internal door service, but I need some guidance.  I want to clean and lubricate things like the window channels, window winder regulator, the door-check straps, and what ever else you feel needs doing at this time.  I will also cut a thick gauge plastic sheet to seal the door cavity before I replace the door card as I know this is missing.  As I have new door lock vacuum diaphragms, I will replace these at the same time.

I have to repeat the process another three times I guess, including replacing the internal window wipes that I have not got round to doing on the other doors.

Oh, and perhaps a visit to Amsterdam in Mrs White before the close of summer.

Keep 116ing ;)

Gavin
1979 450SE "Mrs White"
2022 Touareg-R 3.0TSi Hybrid
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Casey

I did not see that post before Gavin, but I must say, you have a wonderful serviceperson!  I admire the work!

I think my rust-free SEL is about to go into the garage for winter hibernation, which will leave me driving a not-so-nice vehicle but one where further damage from the elements won't bother me.  I've even toyed with the idea of using the rusty leaky partially-dismantled 1973 as a daily driver through this winter.

During it's hibernation, I will be taking the time to rebuild lots of the car and fix anything I can in the process.  Although it's paint looks pretty good from a distance and shines up nicely, it does have a few spots along raised areas where it's worn thin could really use a new layer of paint too, so that may be final step in the process.

I've also discovered that humidity is a major issue here, as a woolen coat in my closet has grown lots of mold, as well as a couple spare leather W116 headrests in my garage!  I think I'm going to invest in a dehumidifier or two for the garage soon.  I gotta say I'm envying Squiggle Dog's relocation to the hot and dry southwest!

jbrasile

Ok Guys,

Here is the infamous drain hole that was added during the bodywork, I put a piece of vacuum tubing through it so you can see the location, it is at the very corner between the firewall and inner fender. Notice how they routed the drain under the fender, looks pretty factory doesn't it....

Hope info helps!

Tks,

Joe






jtwoods4

Wow!!! This is the most comprehensive post on the internet regarding water leaks. Excellent photos everyone! Here is a great video I found explaining how to track down where the leak is coming from.

http://www.youtube.com/watch?v=VbpqoZMpvAc
1980 300SD

oversize

Well I found the thread about the drain holes!!!  LOL!  Here 'tis!

One other thing that I've found extremely important on a W116 is the tail light seals.  Pull out a whole assembly and you'll realize all the rain that lands on the boot lid and the rear window is directed towards the top of the tail light assemblies!  Old, hard and cracked seals will let this water inside to rust out your boot....

All I need is the part numbers and I'll be ordering lots of new ones....  Ye all should be doing the same!  Does anyone know if they're available OEM via other retailers?
1979 6.9 #5541 (Red Bull)
1978 6.9 #4248 (Skye)
1979 6.9 #3686 (Moby Dick)
1978 6.9 #1776 (Dora)
1977 450SEL #7010 white -P
1975 450SEL #8414 gold -P

mrkozzy

#23
hi mate.
tail light seals are around $98 each genuine. getting harder to find.......try John Green Canberra 1st.
The US & German price  was similar, last time I looked.

And another thing.......
Not to put too fine a point on it, the picture below shows what can happen when the water under the floor insulation goes undetected or is not fixed.  I took the 1st picture some months ago of a 116 RHD spotted at the wreckers, that had the accelerator floor hinge completely rusted thru.
This caused me to check my own only to find the drivers side floor insulation wet. It seems the bottom of the accelerator pedal is notorious for gathering a small amount of water content, compounded by mud and pebbles. Obviously this comes every time you get in with wet shoes....the little bit of water has to sit somewhere. The 2nd picture shows my floor pan cleaned of surface rust and the wet (smelly) insulation cut out and thrown away.
The 3rd picture shows the back of my thrown out wet floor insulation and what it looked like from the back side.
I have since sealed the metal and replaced the insulation.
It pays to look!





MrKozzy