Correct Vacuum Hose Material?

[Redfalken]

Less than a year ago I ran a new vacuum line (black rubber hose) to an interior gauge. As I was pulling it off the barbed fitting yesterday where it attaches to the manifold, it almost fell apart. 3 inches from the manifold, it was hard and brittle from the heat. I have a brass junction going into the intake just below the carb. It runs the vacuum modulator on the tranny and the gauge.

So the question is, what type of material should I be looking for that has some heat resistance? Or should I run a hard line for a certain distance before attaching the hose? I'm sure the hose was just something I got at the parts store and I just asked for vacuum hose. I'd like to do it right so I don't have to second guess if I'm getting vacuum leaks.

Also, should the line from the carb to the vacuum advance be a hard line? Right now it is rubber and is quite a bit smaller than the fittings on the carb and dizzy (Autolite 1100 and DSII). I'm putting a Weber DGEV on soon and will need to plumb some new fuel and advance lines anyway. I'm thinking hard lines would be better for the vacuum advance so there's no chance of them collapsing as the vacuum kicks in.

Any thoughts would be appreciated. Thanks...

 

[wallaka]

Look for silicone line. It won't get brittle, but check first to see if it can be used for fuel. Silicone comes in all kinds of fun colors too! :roll:

 

[pedal2themetal45]

HI
I beleve the orginal was most likely a metal line to the back of the block then rubbe to the tranny.
tim

 

[66200i6]

The smaller size is not a problem. These systems do not use a large volume or flow; it is really what should be referred to as a signal. So a larger diameter ID is not necessary.

Have fun, Ric..

 

[Anonymous]

They also make a 3/16" line which is like fuel line (has a layer of braid).

Where do you buy hose from? Stay away from Autozone or advance, their vac hose is very poor quality. I get mine from Napa and have never had the problems you are talking about.

 

[Redfalken]

I think I bought the hose from a small, local chain called Action Auto. It had a layer of white braided material in the middle but just isn't holding up. The silicone hose sounds interesting. I think I may just plumb a length of hard line to get it away from the heat of the manifold and then rubber.

On a similar note, my valve cover has a "tab" spot welded on the front corner (see image below) that I've been told is supposed to have some sort of clip that holds the vacuum advance and fuel lines to give them support. I've been told this clip isn't reproduced and is hard to find. Anyone have a photo of one in use?