Heater box re-build

[skiday]

Hi folks

I'm just re-building the heater box and can't remember how the big thick internal seals go. There were no replacements in the seal kit from SNG so I am only assuming they were original:


They can't all stick to the blade, that's for sure' but does the long one stick to the blade and the two short to the body or what?

Cheers

[vipergts]

I think they all stick to the element.

The flap has a sheet of thin foam right across the side that flap down against the air inlet

[christopher storey]

The heater matrix itself needs foam at the header tanks at either end to prevent it rattling around. The flap IIRC has a continuous thin sheet of foam over its surface, about 3mm thick, to provide a seal when it is shut

[skiday]

The seal kit I bought does have the foam for the two ends of the matrix and the sheet of foam for the flap, although I thought it was a rather low density foam comparied to what I took off.

[ChrisC]

I did this job recently... and after a bit of discovery...

1.The Flap itself has a thin foam sheet stuck across the lower surface. Not the pieces show in the picture
2. Those strips of foam stick around the inner edge of the opening into the air box pretty much as your picture shows and the flap closes onto these creating a half reasonable seal. If you look at the inside of the heater box you will know what i mean as the flap sits slightly proud of the box and those foam strips match up against the flap.
3. The heater element has a much denser pad on the narrower sides to stop it rattling around in the box and there is a thin sheet of foam at either end of the heater element where the entry pipes are which again stop it rubbing on the heater box.

The new SNG kit has all these strips but they are not as thick as the ones in your picture.

[PeterCrespin]

Whilst the element seals may well prevent some vibration, their primary purpose is to ensure all air goes through the matrix instead of escaping around it. This is similar to the various foam/felt seals around the radiator and stoneguard, depending on series.

Failure to fit them, or incorrect fitting, isn't catastrophic and many people are unaware of anything amiss. They put the reduced heat exchange efficiency down to 'character' or 'typical Jaguar' marginal heating and cooling system effiicency. Often it is not Jaguars fault but that of whoever nailed the car together badly last time it was apart.

Same goes for the alloy and steel sheet metal parts between the bonnet mouth and the radiator. Some of these items are often missing and people complain about iffy cooling when they really have missing parts.