Small vacuum lines

[mental1896]

Does anybody know where these small lines can be found new? I bought some at oreilly (the shiny one in the image) that were about the same size but they melted.

Also, I've seen plenty of vacuum diagrams here and elsewhere but I've had a hard time gauging what size each line should be. Is there a guide that shows what sizes are required and how much of each for a complete vacuum system overhaul?

[eaglebeek]

The stuff that's sold at O'Reilly's is plastic and won't stand up to under-the-hood heat. Try some nylon air brake tubing. You should be able to obtain it at a large-truck dealer or parts house. It's usually sold by the foot.

Take samples of your existing tubing and hose with you when you go and use that to gauge sizes. I think there are only two or three sizes you will need.

You'll need some rubber hose of various diameters to make connections between the tubing and the various nipples on the carburetor and elsewhere. When you buy hose be sure it's for fuel lines or vacuum lines. Anything else...and especially windshield washer hose...will collapse under vacuum.

Some of the vacuum tubes have adapters to transition to different sizes. It they're rotted you may have to experiment with different sizes of tubing and hose slipped into each other. I don't have a sure-fire formula...it's strictly trial and error.

There are several check valves in the vacuum system. Each has a colored side. These valves are directional. You should take note of which direction a check valve is oriented before disconnecting it so you can connect it as was originally intended.

[mental1896]

Thanks for all the good info.

I recall reading somewhere that the length of at least some of the lines is important for some reason (not necessarily just these small ones). Is this true or can I just eyeball it or even make some a little longer/shorter for convenience?

[eaglebeek]

There were undoubtedly some engineering considerations in the length and size of the vacuum lines. As a practical matter...I doubt you would experience any problems with performance or emissions if your replacement lines are a bit longer or of differing sizes. I haven't noticed any difference after replacing some of the lines on our Eagle.