expansion tank

[scooby69]

due to a cracked head i have fitted a genuine toyota head ,rad & cap, thermostat,
head bolt & gaskets, i have done 2500k and still loose water into the tank about a pint depends how i drive, i have towed and it does not over heat not even on a long journey from france.the rad stay cold at the bottom and looking into the rad cap i can`t see the water circulating , i can feel the water getting hot if i keep my finger in the rad so it must be circulating a bit.
i did not change the pump but what can go wrong with that as theres not a lot to it!!!!. any ideas.

[coolsv650]

due to a cracked head i have fitted a genuine toyota head ,rad & cap, thermostat,
head bolt & gaskets, i have done 2500k and still loose water into the tank about a pint depends how i drive, i have towed and it does not over heat not even on a long journey from france.the rad stay cold at the bottom and looking into the rad cap i can`t see the water circulating , i can feel the water getting hot if i keep my finger in the rad so it must be circulating a bit.
i did not change the pump but what can go wrong with that as theres not a lot to it!!!!. any ideas.

this is a really silly question but you have got the back heater bled and working? it's a very long way if it is airlocked, also have a quick check on the water hoses, I once had a similar problem turned out to be a leaking hose that only leaked whilst the engine was warming up, once it was a normal temp the leak stopped