Quick brake booster/headlight vacuum question...pic inside
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Instructor
Joined: Jan 2010
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From: Buffalo Gap Texas
Quick brake booster/headlight vacuum question...pic inside
I got started today sorting out the weak headlight issue on the 79 I just picked up and while tracing and checking vacuum lines, I found what is probably the problem. Whereas one of the lines from the diverter valve is supposed to run to the far-driver-side port on the reservoir tank, on my application it is instead capped and terminated at the valve (B in the picture below). The line from that port on the tank instead runs to the brake booster (A in the picture below). Obviously, this is not correct, but my question is what should be hooked up to that port on the booster once I move the line back to the diverter valve where it belongs? If I am thinking correctly, can it just be capped, since its only purpose at this point is to provide vacuum to the tank? Or is it actually drawing a vacuum from the tank and using that to properly operate the brake booster?? Also, all the lines inside the car are ran properly to the light switch and pull down, this is the only wrong routing of the lines that I can see at this point.
Thanks in advance for any help! Only had the car for a couple days so I don't have my FSM yet.
Thanks in advance for any help! Only had the car for a couple days so I don't have my FSM yet.
Drifting
Joined: Jul 2007
Posts: 1,889
Likes: 23
From: Kansas
Yes Sir; My 1980 & 1982, had no second opening. Cap it off, Both of these cars only had the line from the rear of Carb. Which it looks like that is where it is going on your car. Have a great day. Gene
Thread Starter
Instructor
Joined: Jan 2010
Posts: 153
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From: Buffalo Gap Texas
Thanks for the quick response. Can anyone tell me if this looks like the original brake booster/MC setup? I figured it might be an aftermarket or later model application. I went ahead and moved that line to the diverter valve and my headlights are much more cooperative. (Haven't driven it yet, so not sure if I've changed the braking at all). They still just give me a "psshhh" when I try to turn them on without the engine running, so I'm guess there's a leak at the actuator that is greater that what I can supply it with the engine off. One way or the other, much better than before.
Drifting
Joined: Jul 2007
Posts: 1,889
Likes: 23
From: Kansas
Yes Sir; The vacuum line to the tank should be coming off manifold, usually the threaded hole between the Carb. & the dist. Need to run a vacuum test, to find your leak faster. You can buy a kit to test from Harbor Freight. The Vacuum systems, holds around 14 PSI. Willcox Corvette, has it shown on one of their sites, I would think. Or buy the book ( Troubleshooting the 1968--1982 Corvette Headlight & Wiper door Vacuum Systems. ) I bought a complete hose set up & the book.. The Computer was to far away. LOL Good Luck Have a great day.
Thread Starter
Instructor
Joined: Jan 2010
Posts: 153
Likes: 0
From: Buffalo Gap Texas
Yes Sir; The vacuum line to the tank should be coming off manifold, usually the threaded hole between the Carb. & the dist. Need to run a vacuum test, to find your leak faster. You can buy a kit to test from Harbor Freight. The Vacuum systems, holds around 14 PSI. Willcox Corvette, has it shown on one of their sites, I would think. Or buy the book ( Troubleshooting the 1968--1982 Corvette Headlight & Wiper door Vacuum Systems. ) I bought a complete hose set up & the book.. The Computer was to far away. LOL Good Luck Have a great day.
