Heater flap / foam replacement and other interior maladies

[carl888]

The time has come, the heater flap foam.  Had a look through the archives, it's either really hard or really easy, I suspect the latter!

Anything specific I need to watch when doing the job?  I would prefer to do this...............once!  What are you people using for the foam itself?

Finally, can you do the foam without removing the dash?

How this began......I've been chasing a slight water leak from the LHS lower windscreen and after applying some Sikaflex between the glass and the rubber thought it cured.  Imagine my horror after washing the car to find the passenger and drivers side footwells damp.  As it turns out not only was water creeping under the glass (Now cured) it was also coming in through a loose grommet in the firewall that located the bowden cable for the hood release on the LHS.  On the drivers side I cannot say for sure, but it appears a small drip was coming through the base of the fusebox. 

I pulled up both mats and underlay to find standing water where the floor meets the firewall plus on the passenger side, some surface rust.  You do not want rust on a W116.   Realising I now have to remove the seats and centre console, I may as well do the heater foam.  Joy of joys.

[carl888]

Here's a picture of the grommet that's not sitting in the firewall correctly.  It covers the hood release cable.




And from the inside:

[carl888]

The floor........  Passenger side:

[carl888]

Drivers side fusebox area under hood.   (This is a RHD W116):




And from the inside:

[carl888]

It's depressing to consider that most of this needs to come out!

[daantjie]

Good luck that is one prick of a job

[carl888]

Good luck that is one prick of a job

Thanks for the good wishes   

I have sort of been in there before, he's an image from about 9 years ago when I re-dyed the centre console and tidied up some errant radio wiring.  Of course, the heater controls worked beautifully then, nor were there any water leaks!

[carl888]

The OEM underlay is NLA.  has anyone used Dynamat to replace the floor insulation?  It's come highly recommended from some friends in the trade:

http://www.dynamat.com/automotive-and-transportation/automotive-restoration/dynapad/

[oversize]

It's an ugly job, but if you're not in a hurry it doesn't really matter.  The most important thing is to record your progress with photos so that you can put it all back together correctly!

The importance of clear drains and sound grommets cannot be overstated on a W116!  Once water starts to invade the interior, it'll destroy the car in no time.

I'd definitely be looking at aftermarket insulation since the original stuff is old tech and likely to degrade quickly.

[carl888]

Thanks Mark.   Yep, looking forward to playing with the firewall grommets and the heater box, I'll be sure to take plenty of pics!

[s class]

Carl, others might correct me, but I can't see how you would remove the airbox to re-foam it unless the dash is out.  Dash removal would be a crying shame on that car of yours due to the almost inevitable damage that results to the dash. 

I have used dynamat as a replacement of the original floor pads on several cars, and I was happy enough with the results, though it looks very non-original. You might also check their product catalogue, and look at dynaliner, its more of a closed-cell foam type product that would be a closer replacement of the original than the commonly seen foil/bitumin dynamat.

[tcj]

Carl,

the heater box can be removed without removing the dash. Of course the center console must come out.
See chapter 83-100 in the workshop manual, this is the only way this should be done.
Refoam all 8 flaps.
Plan a day to remove the heater box, 2h to redo the flaps and another day to reinstall the heater box.

Water from behind the fuse box: this will be one of your bigger problems, should be corrosion, not easy to access.
Do it while the heater box is out, you may need the extra space on the inside.

Thomas

[s class]

THomas, thanks for correcting me.  Its good to hear that the air box can be removed without disturbing the dash.

[tcj]

Carl,

and you will need (dark grey) modelling clay to redo the sealing between upper and lower part of the heater box.

regards,
Thomas

[ptashek]

I have used dynamat as a replacement of the original floor pads on several cars, and I was happy enough with the results, though it looks very non-original. You might also check their product catalogue, and look at dynaliner, its more of a closed-cell foam type product that would be a closer replacement of the original than the commonly seen foil/bitumin dynamat.

The dynamat is designed as a "stiffening" component, to shift resonance frequency of a panel. The dynaliner typically should go on top of it, for sound proofing.
At least that's what my restorer claimed, and did on my car, so opinions may vary