Water Leak into Drivers Footwell

[jaymanek]

Hi All,

I have been chasing down an issue on one of my 500E with water trickling down into drivers footwell when heavy rain.

So I have now removed enough trim and items to be able to see that water is building up in the HVAC bowl if a lot of water is poured down there.
So a small constant stream of water is managed fine. Once I incrrease flow and the water starts to build up, the water is passing into the cabin.
This gasket (215) is totally wet.

Now my question is... im sure water should drain before it gets that high up in the bowl (drains appear clear) as a foam gasket will never hold water back anyway.

What am i missing!!?

 

[gsxr]

The HVAC box should drain through the 2 ports on the bottom, out the foam tubes #230. Make sure the ports are not blocked. The foam tubes are NLA so if they are damaged when remove them, you will need to find a suitable replacement. They exit above the transmission underneath the car.

Photos here:

Index of /images/W124_dash/evaporator_drain_tubes

 

[jaymanek]

Hi,

Yes ive replaced those tubes with W210 items, thats not the cause of the leak i dont think. these drain the condensation from A/C Evap as far as i understand.

The water is actually seeping through the heater box (under the wiper mech) to firewall seal...

I cant see any blockages, the funny cow teet shape drains are clear...

 

[gsxr]

I am confused about the source of water causing the leak inside the car. If water enters the heater box through the air inlet grille on either side of the wiper, it goes into the heater box, and drains out the foam tubes. If the ports and tubes are clear, water inside the heater box should drain out.

 

[jaymanek]

Hang on, im upside down under the dash of the car, video to follow.

 

[jaymanek]

This is above the accelerator pedal, well above the hvac drain tubes.

The second part of the video shows the drains above transmission bell housing totally clear.

I see a dash strip in my future.

 

[jaymanek]

I think I may have had a eureka moment

 

[gsxr]

Ah, I forgot about the other drain! See photo below. I wonder if that is plugged with debris??

 

[jaymanek]

Thanks but those are flowing nicely. But i found the source of the problem. Thankfully not a dash strip!!

 

[jaymanek]

For future ref, these items.

 

[nocfn]

I always wondered if those need to have a piece of PVC situated in there to keep them open and draining.

 

[jaymanek]

I always wondered if those need to have a piece of PVC situated in there to keep them open and draining.

Yes mine were obviously heat damaged. Shrivelled and directing water totally the wrong way.

I made a temp repair whilst i wait for new ones... Today in heavy rain, no more water! Wahey!

 

[nocfn]

Ah, I forgot about the other drain! See photo below. I wonder if that is plugged with debris??



View attachment 191803

This is the drain I was referring to. One can see both the DS condensor drain from the cabin above the shift linkage and the outer cowl drains. Those flappy ends are not cow utters, they could use some 1' pvc rounds to keep them open me thinks. But they may stay somewhat closed without pressure so rodents do not make their way there.

 

[Seangbadee]

Hi,

Yes ive replaced those tubes with W210 items, thats not the cause of the leak i dont think. these drain the condensation from A/C Evap as far as i understand.

The water is actually seeping through the heater box (under the wiper mech) to firewall seal...

I cant see any blockages, the funny cow teet shape drains are clear...

Since the factory drain hoses are no longer available, I went ahead and got the substitute hoses—two of them, part number 2108300396—along with two clips, part number 1269950046, one set for each side. I removed the rubber ends from each of the drains, ran the foam hoses through the chassis, and that resolved the issue on both sides.

The clips, however, wouldn’t fit around the 210 hoses, so I left them off. The fit was snug enough without them, so I’m confident they’ll stay in place—time will tell.