Will or can the solider(same used in car electronics) melt?? I used a "T" adapter to split the coolant so i can add a water temp guage doing so broke the OEM bleeder screw. I heated up a good amount of solider and melted it inside the hole so antifreeze wont spew out. Can the heat generated from the motor or even the coolant melt the solder??

 

If the solder's melting point is around 210 degrees it will melt out.

It's probably going to leak anyway due to the different expansion rates.

 

Solder's melting point will be 350F and above so if it melts you have bigger problems. And most solder is eutectic meaning it's melting is point is a point, not a range.

Most old school radiator tanks are soldered to the core.

 

can i just forget about the bleeder and plug it with the temp sensor gauge ir is it REALLY nessesary??

 

The bleeder sure helps getting the air out of the cooling system. If your car starts overheating from the air pocket I guess it REALLY was necessary.