Last time I replaced vacuum line was about 7 years ago. The hose was broken in one place and a lot of rubber fitting hard hose connections were stretched and loose.
My major concern is sealing hard hose (alum. or plastic) to rubber fittings. Last time I did this i used a dab of silicone on platic tube, inserted the hose into rubber fitting and topped it off with epoxy.
This was good for 7 years. When I open up, I will know for sure where it has failed.
Once I determine where it failed and why will dictate what material and what needs to be done.
With all you guys cheering on I better find some worthwhile solution.
