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ancient vacuum lines...

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tfhofstad View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote tfhofstad Quote  Post ReplyReply Direct Link To This Post Topic: ancient vacuum lines...
    Posted: Feb/01/2023 at 3:19pm
I have a 80 Concord with the GM 2.5 and the miles of black spaghetti are rock hard and leaky.  By chance does anyone know the size(s) used?  I want to buy enough to replace all the vacuum hoses but there seems to be sae and metric sizes as well as rubber and vinyl/silicone.  Thanks for any info
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***79 Concord 25yr edition
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Post Options Post Options   Thanks (1) Thanks(1)   Quote ramblinrev Quote  Post ReplyReply Direct Link To This Post Posted: Feb/01/2023 at 4:51pm
You are going to have several sizes! Just buy a bunch and good luck!
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Post Options Post Options   Thanks (1) Thanks(1)   Quote FSJunkie Quote  Post ReplyReply Direct Link To This Post Posted: Feb/02/2023 at 1:43am
It's probably mostly run with 1/8-inch (dash-2) nylon plastic line with rubber hose pieces used for connections at the ends. 

Most any auto parts store 1/8-inch nylon tubing for medium and heavy duty truck air brake use. It's cheap and is more reliable long-term than running rubber hose everywhere. Looks cleaner, too. You can bundle it and make it look neat. 

Otherwise, the rubber lines will mostly be 5/32-inch with some 1/4-inch mixed in. PCV is nearly always 3/8-inch. 

Silicone hose will last a whole lot longer than rubber. Like, 50 years longer. AMC actually used quite a bit of silicone hose as OE. You can buy it at auto parts stores. Gates makes it. It's orange. 
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Post Options Post Options   Thanks (1) Thanks(1)   Quote Trader Quote  Post ReplyReply Direct Link To This Post Posted: Feb/02/2023 at 7:18am
And remember to replace one at a time. DON"T remove them all a once or you will be hours with the TSM that in some cases, will still leave you questioning.
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MIPS View Drop Down
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Post Options Post Options   Thanks (1) Thanks(1)   Quote MIPS Quote  Post ReplyReply Direct Link To This Post Posted: Feb/02/2023 at 2:32pm
I'm fairly certain that when I re-tubed the Eagle I only used two different sizes and a bit of fuel-rated line for the carb vents and PCV. I do not have those sizes written down in front of me.
One thing I do remember was that there was at least one inside diameter I could not source, but determined that unless I was running lengths ten feet long the smaller diameter tubing I ordered did not cause flow restriction issues.
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