My 03 Grand Caravan is overheating.
I just changed the radiator because the old had a small leak.

I have checked the fluid level,made sure not a lot of air in the system.
Pulled the thermostat to see if that would help.

The weird thing is the old rad leaked but it did not overheat UNLESS I completed filled it up.This confuses the hell out of me.
If I completely filled it up it would overheat.But as soon as some of fluid leaked out it drove fine.

Now with new one in it is overheating as soon as I drive it just a little ways.

I did notice the top hose of rad is very hot.However the bottom one is not.
The rad cap is not to hot either.
So is the water not circulating or something?

Please,really need some help with this.

 

If you're certain there is no air pocket, it seems like the only thing left is the water pump. It's a very common failure on these vans - has it ever been changed on your van? It usually leaks as a first symptom, but perhaps not always. Can't explain why it doesn't overheat when not complelely full - maybe there's some convection going on, which is helping the dying WP.

 

What do you mean by convection? And I am beginning to suspect water pump too.
I just finished putting the old leaky rad back in.And after a test drive it is no longer overheating.Why this is I have not earthly idea.

I was wondering if it has something to do with the pressure in system.
With this old leaky rad it can not build up pressure in the system like the new non-leaky one.