My guess is that it isn't the lines, they are pretty hard and durable, but more than likely are the parts they attach to, such as the vacuum control modules.
These do wear out. Depending on how exten$ive the process, it is always a good idea to replace all of them where you are there.
I just had to do a
dashadectomy on the 190e and I definitely replaced all the vac mods.
Haasman