Houston we have a problem....

Hi guys n gals,my landy has developed an annoying drip of coolant Its not a large amount,i've been having to top up with approx 1ltr every couple of weeks.I've been underneath and cant see where its coming from,I've looked from above and i'm still clueless I thought i'd found the problem yesterday as the bottom left hand corner of the rad did seem a little wet,I checked the sill under the rad and it was bone dry In went a bottle of rad weld just incase but much to my annoyance the drip still remains any ideas/suggestions gratefully recieved.
Bet.

could be a weak spot somewhere on the rad. the reason you cannot see it, is that its drying off before you can spot it.
also could be the overflow pipe from the expansion tank? try a new pressure cap.

use coloured coolant. like bright green. i've tried that and found the leak i was looking for.

I had a Ford Ranger that mysteriously lost antifreeze for 5 year. After replacing the heater core, radiator, cap, and all hoses it still kept disappearing. It disappeared faster during the winter than the summer. I figured it might be a pinhole at the freezeplugs or at the water pump seal. But reached the conclusion that it would take a whole lot of coolant to equal the cost of any further work and easier to put coolant in every week or two, or at least until it became obvious.

My Landy had coolant dissapearing now in all this hot weather ( on my way Back from England to Sweden ).
No matter how hard I loked I could not find and tell tale drips etc..
The engine wasnt using it either......BUT.

I discovered in the end that the expansion tank was leaking around the seal ( where the two halves are put together ) and as it is hot, the drips were simply evaporating , leaving no "sign".

( why dont they make them as a whole as opposed to 2 halves ?, it has to be a weak spot ! )

Anyway....a replacement is only about £ 16 and easy to fit.

Check the front carpets around the tunnel if they are damp its yer heater or hoses...good luck feller...

It was the rad after all fitted a new one,prob sorted thanks for the input all