Coolant leak from the radiator cap

Did you clean the rad. very well where the rad. cap seals inside the top of rad.?

 

Overfilling with coolant?

 

did you bleed the coolant system?

also check the overflow container where the cap goes.

 

Poke a hole in the bottom and it won't leak out of the top! It could be over pressuring from a bad head gasket

 

Start with a cooling system pressure test.

 

Make sure you aren't filling expansion tank above the MAX line when cold. Coolant expands when it gets hot and if there's no expansion room it will spit coolant past the cap.

If you're good with the coolant level next step would be the pressure test as recommended above.

Frank

 

The build up of old coolant under where the cap is trying to seal on top of rad is where you need to clean so the new cap can seal, be sure you did not buy a china made copy of a real cap? if a china made was found go buy a real cap!