Intro & Vacuum Question
Thread Starter
2nd Gear
Joined: Oct 2023
Posts: 2
Likes: 1
Intro & Vacuum Question
Hello All
Purchased my first vette, 1970, and excited to find these forums. Already seems like a wealth of information. While I’ve owned number of muscle cars I’m finally going to use this one to learn and work on it myself now that I have the time so apologies for novice questions.
Question: When working on, in this case, the vacuum system is there a best place to start; can you test parts somehow first or do I just need to replace components until it works? Specifically the wipers don’t work. I’ve found the diagram but other than confirming the fuse is good not sure where to dive in. I’ve noticed the headlights go up slow but doesnt seem like there were any leaks.
Purchased my first vette, 1970, and excited to find these forums. Already seems like a wealth of information. While I’ve owned number of muscle cars I’m finally going to use this one to learn and work on it myself now that I have the time so apologies for novice questions.
Question: When working on, in this case, the vacuum system is there a best place to start; can you test parts somehow first or do I just need to replace components until it works? Specifically the wipers don’t work. I’ve found the diagram but other than confirming the fuse is good not sure where to dive in. I’ve noticed the headlights go up slow but doesnt seem like there were any leaks.
Safety Car
Joined: Dec 2012
Posts: 3,796
Likes: 1,706
From: Summerville SC
All you need to do is get a hand held vacuum pump. You can then hook it directly to the component and determine if it works. You also need to get yourself a diagram of the vacuum system. There are lots of hoses for lots of systems but if you isolate that system, then start tracing the hoses, you will see how it works. Just start with one system. like your wipers. But those are electric, right? You have a vacuum wiper door, which is another system. hook your vacuum pump up in place of the SOURCE hose and pump away. Get the diagram and the pump and you will figure it out. 
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
Here's the old troubleshooting document from mid-america a
And a link the to the vacuum 101 website
https://www.corvette-101.com/vacuum.htm
HIH
M
And a link the to the vacuum 101 website
https://www.corvette-101.com/vacuum.htm
HIH
M
1967 Pedal Car Champion
Joined: Mar 2020
Posts: 9,027
Likes: 4,174
From: US-PNW
Question: When working on, in this case, the vacuum system is there a best place to start; can you test parts somehow first or do I just need to replace components until it works? Specifically the wipers don’t work. I’ve found the diagram but other than confirming the fuse is good not sure where to dive in. I’ve noticed the headlights go up slow but doesnt seem like there were any leaks.
The headlights and wipers are two separate systems with a common vacuum source. I'd suggest tackling the slow headlights first to gain familiarity with the components. First I'd locate the vacuum tank under the driver's fender and cap off/disconnect the wiper side of the lines. If you have a major leak on the wiper side, the headlight side will be affected. You also need to be aware that there are a number of vacuum hose connections behind the driver's dash -- listen for any hissing with the engine idling.
Follow the entire system of hoses from the engine to each component to ensure all of the rubber lines are in good condition with firm connections (you can trim off 1/2" or so of hoses to get to a non-stretched section). You can go so far as to measure engine vacuum at the vacuum port where the headlight/wiper system gets its vacuum and then along the components to see if there's any significant loss in a section.
Burning Brakes
Joined: Oct 2002
Posts: 1,040
Likes: 109
V
Hello All
Purchased my first vette, 1970, and excited to find these forums. Already seems like a wealth of information. While I’ve owned number of muscle cars I’m finally going to use this one to learn and work on it myself now that I have the time so apologies for novice questions.
Question: When working on, in this case, the vacuum system is there a best place to start; can you test parts somehow first or do I just need to replace components until it works? Specifically the wipers don’t work. I’ve found the diagram but other than confirming the fuse is good not sure where to dive in. I’ve noticed the headlights go up slow but doesnt seem like there were any leaks.
Purchased my first vette, 1970, and excited to find these forums. Already seems like a wealth of information. While I’ve owned number of muscle cars I’m finally going to use this one to learn and work on it myself now that I have the time so apologies for novice questions.
Question: When working on, in this case, the vacuum system is there a best place to start; can you test parts somehow first or do I just need to replace components until it works? Specifically the wipers don’t work. I’ve found the diagram but other than confirming the fuse is good not sure where to dive in. I’ve noticed the headlights go up slow but doesnt seem like there were any leaks.
Please point me in the right direction for one for a 71, No AC, manual trans, convertible model
I've just spent a week going blinder looking at many and my AIM and still haven't made sense of it yet.
Mainly need to understand where they route after leaving the 2 port check valve, 1 goes to vacuum tank = got it
2nd line going inside to ?
Need headlight switch, 2 override switches (yes wiper also) and solenoid switch on back of tach
Thanks in advance
ANYONE ?
Does this look like a CORRECT schematic, courtesy of Mid America
Last edited by 1971corvette; Nov 5, 2023 at 12:14 PM.
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