Vacuum lines

Good morning folks I’m in the process of changing my 89’s vacuum lines and have run into a slight problem. I’ve changed all lines from the firewall to the canister up front so far but I’m having a problem with the line from the bottom of the canister. The line comes out and then splits and disappears under and In front of the hood and radiator.. Can someone please tell me where it goes and how to access it ..?? Any help would be GREATLY appreciated.. Thanks OConn962 (Thomas)