Any easy fix for this, please ? (easy fix = NO radiator replacement)

Not really.... you could try epoxy resin such as araldite but I'd be surprised if it holds up...

there's no way to fix that to be honest, like darren has said above you could try glue but it won't hold...

You could try this stuff

http://www.repairproducts.co.uk/page69.htm

For the sake of the £30 or so it'd cost to buy another radiator, is it worth it? If it fails then at best it could leave you stranded, at worst it could kill your engine...

thank you, guys. I got quick answers from pros as expected.

all info on the net converge towards your point of view: there is no adhesive good enough to stand for a long time repair.

for short time repairs I will consider though testing RapidFix Instant Dual Adhesive.

How did it get broken in the first place? (Just out of interest)

my guess is he had to get brutal with the hose in the course of changing the coolant

it is better to ask than guess, Tom.

the cause is called tear and wear (or material fatigue) after 14 years.

it began as a minor leak that didn't bother me when it was cold outside.

then summer came and I saw one day moist on the pavement in a parking lot.

got home and I was preparing to slightly screw the hose clamp (with a screwdriver, NOT with a sledgehammer) then splash! here goes the coolant on the ground...

Problem solved. New radiator. None of the bonding solutions worked.