1991 STS Brake Lines
 

Hi there. Im a new member and new to the world of Caddy's and need some advice. Firstly can anybody let me know what size the brake unions are? They are rusted through and need replacing, the unions are rusted to the hoses and i dont want to round them off by using the wrong spanner(wrench) Secondly what is the unit that the hard brake line goes into first? Is it some kind of balance valve? I may need to replace these if i cant free the union off. Many thanks in advance. Daz