what is the piece on the driver side near the master cylinder with the vacuum hoses going into it. There is B/B , S/C, A/C, and S. i broke the tiny one that goes to the A/C. my ac is low on refrigerant and has some leak detection stuff in it for when i bring it back in to my mechanic. i am bringing it in on monday but can i drive without that A/C vacuum line. the part where it broke is on the passanger side and it goes back into the firewall so its not like i can get it out of there and just replace it. any suggestions