I need to replace the very thin vacuum lines that go through the firewall into the HVAC control. I can't figure out how to detach them from the block that is attached to the firewall, or how to thread new lines up into the engine bay. Any expert advice here?

Thanks.

 

Have a look here: https://i.imgur.com/AHlTteI.jpg

Red arrow is the block?
Looks like it just clips on to a plastic stand off on the side, never took one off myself

Not sure how hoses are attached, may need to heat them with heat gun/blow drier

Dorman has 1/8" flexible "hard hose", seen here: And ends or couplers as needed

Hard lines are used by car makers because they are cheaper when using thousands of feet and are easier to color code and have made pre-bent, making assembly easier for workers
Rubber vacuum lines work just fine for repairs or replacement of these hard lines

 

Yes, that is it. Looks like the block clips to the firewall. I haven't gotten my head deep enough in there to tell - I'm old and stiff. And so is this hose, so I expect removing it from the block will be a challenge. Once it's free, I suppose I could splice the new line to the back of the old with duct tape and pull it through into the engine bay. That should get it routed correctly.