355T-FS Stewart Warner Vacuum guage/..?

Last yerar I got a working used vintage SW Vac*** guage black backgroung 2.1/4 round All was fine

Just started my truck up and noticed that the guage was not moving much but movied

Took it off put ift on a bench vacuum tester and if I tapped it it works

any timps to get theis working maybe lube in the back or /...?thanks for the info DAniel

 

Short update I ended up turning it upside down and put a few drops of 10weight oil in it and black wall tire shine..

Next day all is fine must of needed internal lube..