71 Vacuum Tank
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
71 Vacuum Tank
I have had my 71 automatic 350 since late last year and have been working through a number of areas.
One is the vacuum system.
It all works well but the wiper door does open and close on startup or after a heavy acceleration.
Have read numerous threads and have been following some of the tips from Roger and others.
I now have a number of items to replace to try and fix it but am more concerned that there is no vacuum tank where the AIM shows one.
Should all cars have one ?
I dont even see evidence of where brackets may have once been.
One is the vacuum system.
It all works well but the wiper door does open and close on startup or after a heavy acceleration.
Have read numerous threads and have been following some of the tips from Roger and others.
I now have a number of items to replace to try and fix it but am more concerned that there is no vacuum tank where the AIM shows one.
Should all cars have one ?
I dont even see evidence of where brackets may have once been.
Race Director
Joined: May 2006
Posts: 16,528
Likes: 53
From: Dayton, Ohio
All cars did have one but obviously don't have to have one for the system to operate when the engine is running. If you ever needed the headlights or wipers during heavy acceleration (up a steep hill) they would not work until you let up on the throttle. Most can get by without a tank.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,118
From: Crossville TN
The tank is an accumulator which 'stores' vacuum for use by the wiper door & headlights. It guarantees [well, when there aren't any significant leaks, anyway] that those components will operate smoothly and quickly when they are activated.
Probably more important than the tank is the vacuum check valve in the main line off the intake manifold. If it is not there or defective, that stuff may, or may not, work at various times.
P.S. If you need a tank, your best option is to buy a good one at a Corvette parts swap meet.
Probably more important than the tank is the vacuum check valve in the main line off the intake manifold. If it is not there or defective, that stuff may, or may not, work at various times.
P.S. If you need a tank, your best option is to buy a good one at a Corvette parts swap meet.
Last edited by 7T1vette; Jul 4, 2010 at 07:55 AM.
Melting Slicks
Joined: Jul 2009
Posts: 3,264
Likes: 3
From: Vero Beach FL
Hello 71
Yes your car should have a vacuum tank. It fits above the vapor canister under the driver side fender surround sort of between the power brake booster (if so equipped) and the horn relay. The brackets are actually welded to the tank and bolt through (3 I believe) the fender well. I have seen a few for sell from time to time on internet auctions.
Scott
Yes your car should have a vacuum tank. It fits above the vapor canister under the driver side fender surround sort of between the power brake booster (if so equipped) and the horn relay. The brackets are actually welded to the tank and bolt through (3 I believe) the fender well. I have seen a few for sell from time to time on internet auctions.
Scott
Thread Starter
Melting Slicks
Joined: Apr 2010
Posts: 2,794
Likes: 1,195
From: Canberra Australia
2025 C3 of the Year Finalist - Modified
Thanks for the posts guys.
Finding one in Australia may be a bit more difficult so I may buy a generic one or try and make one.
I saw it mentioned that you could possibly make one from PVC pipe and then fit some brass outlets.
I assume there are no valves etc its just straight through as the check valve is doing the sealing.
So having no tank could be the cause of the door opening under hard acceleration then ?
Regards
Craig
Finding one in Australia may be a bit more difficult so I may buy a generic one or try and make one.
I saw it mentioned that you could possibly make one from PVC pipe and then fit some brass outlets.
I assume there are no valves etc its just straight through as the check valve is doing the sealing.
So having no tank could be the cause of the door opening under hard acceleration then ?
Regards
Craig
