1989 325i Master Brake Cylinder Help

[Pro1914]

Hello, please forgive me if this isn't the right place to post this. I couldn't find anything else relating to this. Also, please be aware that I am just getting into cars, and maybe wrong with something I say or mention.


My 325i's hand brake has been removed by the previous owner. He opted instead to install a hydraulic brake. I want to revert it back to the standard hand brake, but I am unsure what the original master brake cylinder lines looked like. Currently, he has a single copper pipe running from the front-most hole, through the firewall, into a hydraulic cylinder, then from that back to, what I would assume is the rear brake lines. What originally went in the second hole, if anything at all? Can I safely remove it? Thank you so much in advance for stopping and taking the time to help me out here.


[Engine Bay]


[Hydraulic Cylinder]

[KIRIEIW]

From the factory, you have two lines leading from the ABS pump directly into the master cylinder. Do you still have the ABS pump in the car?

[Pro1914]

That's exactly what I needed to know, thank you! Yes, the ABS pump is still in the car, it's just been relocated. Does ABS even work with just one line leading into it? Just curious.