Radiator Cap Leak

[twincamrider]

Originally Posted by dingocooke

Sounds to me like the blanking cap on the rad neck is either u/s or not sealing properly as normally a leak from pressure would first be at the expansion tank neck.

I would investigate the fit/seal of the blanking cap and try another one.

Will do, thanks and if necessary I will order a replacement cap.

[dingocooke]

Originally Posted by twincamrider

Will do, thanks and if necessary I will order a replacement cap.

out of interest is this a new build and its leaked when started or has it started to leak after youve been driving it a while???
#

[twincamrider]

Originally Posted by dingocooke

out of interest is this a new build and its leaked when started or has it started to leak after youve been driving it a while???
#

Its a new build, new rad etc, have done about 250 miles.

[dingocooke]

Originally Posted by twincamrider

Its a new build, new rad etc, have done about 250 miles.

OK thats why I asked if its leaked from day 1 Id say it was the wrong cap.

[lutman]

Originally Posted by dingocooke

Sounds to me like the blanking cap on the rad neck is either u/s or not sealing properly as normally a leak from pressure would first be at the expansion tank neck.

I would investigate the fit/seal of the blanking cap and try another one.

Would agree with this - the cap should have a rubber seal inside the cap, it deforms slightly when installed and should show signs of where it makes contact with the rad itself, if its not an even contact all round, that is shows signs of contact on one side more than another then perhaps its the cap, also consider making another "gasket" for the cap out of suitable size rubber ( like an old inner tube ) and see if that seals ok ?

[aksportscars]

Mark, your rad cap has to seal at the bottom. If it only seals around the top then your water will not be under pressure and it will continue to chuck it out of the overflow.

Regards Lynda

P.S. Thank you for the card

[dingocooke]

Originally Posted by aksportscars

Mark, your rad cap has to seal at the bottom. If it only seals around the top then your water will not be under pressure and it will continue to chuck it out of the overflow.

Regards Lynda

P.S. Thank you for the card

Hi Linda,
From what Mark has described, he has a rad with a pipe from the overflow to an expansion tank; I assumed from hois description he has a blanking cap on the rad with a pressure cap on the expansion tank and the rad overflow pipe going to the expansion tank. This should work, but maybe Ive misunderstood what he has?

[aksportscars]

No, he has no cap on his rad. The rad is filled via the expansion tank.

Regards Lynda

[dingocooke]

Originally Posted by aksportscars

No, he has no cap on his rad. The rad is filled via the expansion tank.

Regards Lynda

OK Im confused now (not unusual) so does his expansion tank connect to the rad neck 'overflow' pipe connection, or from a pipe elsewhere in the rad if its the former Id have thought he would need a blanking cap on the rad, and a pressure cap on the expansion vessel,
If its the second I can see where youre coming from and he should have a pressure cap on the rad and the blanking cap on the expansion vessel so his problem would then be is he has the caps mixed up and he should take the blanking cap off the rad and put it on the expansion tank, and pop the pressure cap on the rad.

Do you agree??!!!!

[twincamrider]

Lynda, I don't have the standard AK set-up, it is a blanking cap on the rad and the overflow is conected to the expansion tank. The problem is the blanking cap on the rad leaking......somehow I need to get a proper seal on it.