Swan neck

[blueone]

Anyone change the radiator cap neck on the swan neck or even have a spare complete one as my cap will not seal and I am get fed up with arriving in a cloud of steam. Tried 3 caps so more drastic surgery called for now

[dickymint]

Try Tim Lamont here http://www.actproducts.co.uk/hoses.php#engine he does shiny stainless ones with cap.

[pwd95]

The one on the swan neck has no spring remember. It's just a plain cap with a rubber seal. The one on the expansion tank is the pressure cap

[BrianTVR350]

Phil,

I was going to ask a daft question...

Are you using the correct type of radiator cap? The swan neck should have a "blank" cap i.e no spring and sealing washer, just a large rubber sealing washer.

The dreaded plastic reservoir has the pressure relief variety with the spring and small sealing washer.

If you get them the wrong way round you can have all sorts of fun!

Regards,

Brian (and a Red350i)

bet me to it!!!

Edited by BrianTVR350 on Wednesday 1st August 12:33

[blueone]

Yes Have caps correct way round just wornout/damaged neck so cap will not seal.

[pwd95]

Halfrauds might have em, or your local rad 'recorer'

[adam quantrill]

Use blue hylomar on the swan neck cap. Ignore the swan neck cap in the future, and only top up the expansion tank. During topping up, give the top and bottom rubber hoses a few tweaks to get any bubbles out.

[TVRleigh]

Or you could wrap some wet and dry round a very flat metal or hard wooden block, then flaten off the face of the swan neck. this should give you a better seal.

[ed_crouch]

The bit that makes me laugh is that TVR went to the bother of making em out of stainless, then welded the filler neck on with Mild Steel MIG wire...

Ed.

[PHart]

Have the same problem! When it was pi$$ing all over my MOT tester (top bloke, he still passed her, despite the bad behavior!) he said that type of cap was never made for continuous removal. Ie: it starts to leak, you pull it off, top up, it leaks some more, off it comes again, etc, etc... Basically he said the seat deforms over time, and you can forget it ever sealing again. I have been through four different caps, have tried using thicker rubber as the seal, nothing seems to work! I am now looking at having a blank welded over where the cap should be (still allows for the expansion tank pipe)and fitting a bleed vavle into a heater hose for air removal.

[TVR 3X]

I got a blank cap from Car Builder Solutions <www.carbuildersolutions.co.uk> at £6.50 plus £2.50 p&p + vat - total £9.99 - Page 12 in their online catalogue - it worked for me!

Russ

[adam quantrill]

What some other people have done is fit a large proper plumbing fitting onto the opening on the swan neck. You should be able to get a large threaded brass coupling that will fit into the hole. You can then either braize it in, or probably liquid metal would work well.

Then you have a proper seal when you screw in the insert (e.g. a brass plug), and the luxury of still being able to top it up there if necessary.

[350zwelgje]

Sometimes it is not the cap (my case). There is a small connection just below the cap (going into some hose back to the overflow thingy...?). This connection tended to leak, and it was the hose clamp due to the small diameter.

By the way I was able to 'repair' my existing cap to seal even more properly. Long time ago so don't remember what I did. And the issue of the small connection was only identified after when I knew the cap sealed properly.

Rob

[TVRleigh]

Also if you have a spare blanking cap, but this on the expansion tank, then use the overflow connection from the header tank and connect to a foot pump, pump the foot pump to 15-20 PSI, if this holds then there's no leaks.

If it drops you should be able to see where its comming from with out having to worry about the engine heat, over heating or the belts. etc.

Also Not checked but it should be posible to cut the spring off a presure cap to make it into a blacking cap.