What is this??

[SASKCHEYENNE75]

Hello all,

I'm doing some cleanup on my 75 Chevy C10 and some long overdue maintenance. Can someone tell me what this is? It sits right in front of the distributor and has a vacuum hose coming off of it. Sorry for the photo quality...its not great. Thanks!!

S

You must be registered for see images attach

 

[DoubleDingo]

Vacuum line for the modulator valve? Follow that line and see if it goes to the transmission, I bet it does.

 

[SASKCHEYENNE75]

Vacuum line for the modulator valve? Follow that line and see if it goes to the transmission, I bet it does.

Hmmmm I think you just may be right!!

 

[SASKCHEYENNE75]

Another question.....does the vacuum hose attached to the distributor vacuum advance supposed to go straight to the carb??

 

[DoubleDingo]

Depends on the application. Manifold vacuum, ported vacuum, that is the debate of the century. If you have the original air cleaner assembly, check the sticker on it and how the lines are routed.

 

[SASKCHEYENNE75]

Depends on the application. Manifold vacuum, ported vacuum, that is the debate of the century. If you have the original air cleaner assembly, check the sticker on it and how the lines are routed.

Ok gotcha....I think mine goes from the manifold but I can't be sure because there is no sticker left on the air cleaner. There is a short vacuum hose that goes from the vacuum advance to the manifold somewhere by the distributor then a long vacuum hose that comes out from the same area that leads to the carb so I'm assuming that is right? Just looked funny to me but I guess if thats the way it was then just leave it like that

 

[DoubleDingo]

That port on the back of the carb is manifold vacuum, there is nothing obstructing it as it goes directly through the back of the base plate. If your truck runs well, leave it as it is. If you have vacuum leaks from bad vacuum hoses, put new hose in but same routing if it runs good as it is.

 

[SASKCHEYENNE75]

That port on the back of the carb is manifold vacuum, there is nothing obstructing it as it goes directly through the back of the base plate. If your truck runs well, leave it as it is. If you have vacuum leaks from bad vacuum hoses, put new hose in but same routing if it runs good as it is.

Thank you for your help I will try that!