My vacuum lines were old, hard, cracked, and brittle (20+ years in a hot engine compartment will do that to you) so it was time to replace them. Doing it while the engine was out just made it that much easier, this was part of my replacing the manual transmission project. If you still have the original equipment lines it's time, well it's probably past time to replace them one and all.
I ordered these on eBay
- 3 meters of 6mm green high temperature silicone line
- 3 meters of 5mm red high temperature silicone line
- 3 meters of 4mm purple high temperature silicone line
- 3 meters of 3mm blue high temperature silicone line
I used almost all of it, I could have ordered 2 meters of the 4mm and 3mm but it's not expensive and I didn't want to run short. I used different colors for different sizes to make it easier to keep track of the sizes, and it looks good.
Advantages of the silicone, it is resistant to heat and most things under the hood except fuel. Don't use it for fuel or fuel vapor lines.
If you have a 2wd you won't need nearly as much 5mm