52 chevy temp gauge problem

Help anyone? posting this for a friend, he just replaced his mechanical temp gauge in his 52 chevy pickup, the old one had the end broken were it screws into block. the new one looks nice but wont register anything. Is it just cheap parts or are we missing somthing here? Looks simple enough and seems like heat just travels up the copper line to move gauge. any suggestions ? Ken

 

Some cheaper gauges flat out dont work right out of the box. Best to take it back to the parts store and return it for another one.

 

We can repair the original if you care to go that route.