408 (and others) fresh/cold air ventilation question.

[dwomby]

My car has had the control lever for the fresh air vents removed. The cables to the vents have been cut. The vents seem to be rusted in the closed position. I am wondering how they are supposed to operate. Am I right in thinking the vent opens outward toward the plenum aft of the engine compartment? That they open by the cable pushing them rather than pulling? That the closing flap is not hinged on one side but instead is swung outwards on two pivoting arms and held open parallel to the opening itself.

Any suggestions on freeing the frozen mechanism or am I better off leaving it all as is in case of water entering from the plenum?

Thanks for any help.

David

[408VIKING]

Hi David.
The vent is controlled by pushing the inner cable. Picture 1
The control unit is the same type as AH 3000, and surely other Britsh cars. Picture 2, 3. As you can see in the pictures is it an unversal unit and both static part and handle can be angled differtly.
/Per

[dwomby]

Originally Posted by 408VIKING

Hi David.
The vent is controlled by pushing the inner cable. Picture 1
The control unit is the same type as AH 3000, and surely other Britsh cars. Picture 2, 3. As you can see in the pictures is it an unversal unit and both static part and handle can be angled differtly.
/Per

Thanks for the helpful pictures. I spotted this lever on eBay. It is the same as on a Sunbeam Alpine and, obviously, other Rootes products of that era. I am pretty sure it is the same as the Bristol originally had.

Hopefully I am right (although I need to find a clamp to hold two cables) and I can free up the cold air vent doors.

David

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David Womby
1964 408-7023 Florida/Nova Scotia

[dwomby]

I fitted new cables and a new lever assembly and the fresh air vents now open and close as they should. In the end I opted for a twin lever assembly so that each vent can be controlled independently although I am not sure there's much benefit to that. It was quite inexpensive off eBay and was a BL part for the MG1100. A similar one is available for the Austin 1100. I hope to get proper knobs at some point but for now the levers have rubber vacuum caps fitted as knobs. The whole assembly is quite unobtrusive below the dashboard.

David

[dwomby]

I thought I damaged one of the cable retaining bolts on the lefthand fresh air vent and a closer inspection revealed that I had!

I didn't want to risk it detaching in the future so I decided to replace it. It snapped as soon as I touched it.

The question now was: where the heck do I find a replacement? An internet search and visits to local hardware stores were unfruitful. Then an idea occurred to me and a visit to our local bicycle repair shop produced a suitable part.

I had to enlarge the hole slightly which was really awkward but a curved rattail file got it opened enough.

All done. Cost $2.56 including tax.

David
--
David Womby
1964 408-7023 Florida/Nova Scotia

[DODD]

David,
Reading your notes regarding the fresh air vents on your 408, I have a similar problem on my 410 that the vents have also seized up in the closed position.
The photos you posted of the vents are Identical to the 410; did you manage to remove the flaps and associated mechanism and if you did remove the flaps, are you able to provide a little advice please, or did you carry out your repairs in situ?
As well as freeing the mechanism, I would like to replace the foam seal that’s attached to the inner face of the flap to prevent draughts.
If anyone else has removed these flaps to carry out repairs, their comments would be very much appreciated.
Regards
Brian

[dwomby]

Brian

I got lucky. The vent flaps on mine were not seized. The remnants of the old control cables left attached at the vents were the problem. Once they were removed the flaps moved smoothly. Also my flaps seem to have felt type material as seals and in decent condition. So, for me, no need to remove the whole thing for refurbishment and. frankly, I am not sure I could have got them out.

David

[DODD]

David

After further inspection I decided not to attempt trying to remove the flaps, it looks like they have to be removed from the engine bay which involves removing the heater box etc. and then removing a panel above the firewall; this just wouldn’t have been worth the effort involved.

On the plus side, once the cables were removed and a liberal amount of WD40 applied and a bit of force to free the flaps, followed by 3in1 oil with a ptfe additive, the flaps now work perfectly.
The foam sealing material doesn’t look in bad condition either, so I may leave that as it is.

I also decided to follow you by replacing my single ventilation lever with a double lever which I have purchased as new/old stock from eBay, like yours it comes off an Austin 1100/1300

Thanks once again for your advice.

Brian

[dwomby]

Glad to hear that worked out for you too.

Davif