coolant dripping out of the resevoir after driving
 

what would cause coolant to spill out of the resevoir after I drive my car. You know how the over flow tank has the line from the radiator to it and then on the other side of the hose going into the over flow tank is a tube going out. Well it drips out there why would it do this??? THanks. oh by the way the over fill tank is not full.

Is it filling up and then "leaking" out?

no. just leaking out. Wierd this is, if I open the lid it drips back into the tank???

How is your radiator cap? That has everything to do with how much pressure (or vacuum) is in the overflow tank...

I have a brand new one on my koyo and one that is fairly new on the old filler neck. oh yeah all my coolant stuff is new except water pump. I have taken the cap off of the radiator and unplugged the egi fuse and turned it over and no coolant came out so it is pretty safe to say coolant seals are good.

Did the problems start soon after this "brand new" one was installed? Is it an OEM Mazda cap?

well my car was getting a little hotter and since I"m redoing most of this car I just changed all the cooling components out so I'm not quite sure it was but actually come to think of it yes I used to drive this car to lafayette witch is about an hour and a half from me and it would do the same thing. Could it be the filler tank itself???? oh and no its not oem it is rated at the same I just wanted a cap that I could depresurize.

Yep, could be the tank, but you don't hear of them failing too often...

What do you mean by "I wanted a cap I could depressurize"?

it has the red flipper on the top that you can flip up and it depressurizes the system so you can open the cap while hot.

Have you taken the tank out and "played" with it with some water inside, to see if anything "weird" is going on?

Ahh, now I get the "depressurize" thing...

no not yet but I will see if anything mystikal happens when I put water in it ;) Strange stuff...

bump for any other ideas