Vacum Issues
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Joined: Feb 2004
Posts: 88
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From: MAYWOOD MO
Vacum Issues
Like some of the rest of you, I am trying to iron out some of the little annoying issues with my 71 coupe this winter so I will be ready to drive this spring. This has led me to item #1 on my list: the vacum system. In testing the sysem w/ a vacum gauge, I have found that one port exiting the vacum resevoir has only 2 in hg reading while the other reads around 12 in hg which is also the reading at the manifold.
So, why would one port have a different reding than the other? Could it be an obstruction within the tank itself? Or maybe hoses are hooked up to the wrong ports on the resevoir? Or maybe a leaking resevoir?
Thanks in advance
So, why would one port have a different reding than the other? Could it be an obstruction within the tank itself? Or maybe hoses are hooked up to the wrong ports on the resevoir? Or maybe a leaking resevoir?
Thanks in advance
Drifting
Joined: Dec 2004
Posts: 1,313
Likes: 5
From: Middle Tennessee
I recommend measuring the vacuum going into the reservior to know what the "goes-inta" value is. The vacuum at the outputs (goes-outa) should be the same or pretty darned close to the input vacuum if all is well. The reservoir may have one or more leaks. I have a leak in my headlight system that I haven't chased down yet, but suspect that it may be a leak in the vacuum resrvoir tank. If the system is leak-free, the vacuum should be pretty even throughout. You will see some small losses even in the best system, but shouldn't see a great deal. You can actually locate leaks in the system by "walking through it" with your vacuum gauge. Where you find a significant drop in vacuum indicates a leaking component or vacuum line. It's similar to a water pipe system.
Le Mans Master
Joined: Sep 2003
Posts: 8,812
Likes: 2,029
From: eastern NC
Originally Posted by nelson71
Thanks for the reply. What I am seeing is one output at the same reading as the input, while the other is significantly lower.
Good luck... GUSTO
