1972 Vacuum Tank/Reservoir Replacement
Thread Starter
5th Gear
Joined: Aug 2016
Posts: 5
Likes: 0
1972 Vacuum Tank/Reservoir Replacement
The vacuum tank/reservoir (the one mounted in the driver fender) on my '72 is leaking. I've purchased and installed the vacuum overhaul kit and relays, which are easily found online, but cannot find this tank at any of the typical catalog companies. I'm finding things on ebay used for $120 and new for $230, but it's odd to me that there's nothing in the catalogs to replace this. I can find one for 80-82 for $50 easily, but I'm not sure why there's nothing for any other C3. Does anyone know where there's a reasonable replacement or has anyone had experience fixing or replacing with something different?
Team Owner
Joined: Sep 2006
Posts: 31,160
Likes: 4,236
From: Westminster Maryland
Hi s,
Welcome!
First Post!
And a 72!!! Nice!
The tanks do sometimes end up leaking. Some folks have success in repairing them depending just what the problem is…. rust ?, a crack?, a leak at one of the hose connection pipes?.
You're right. There isn't anyone making reproductions of these tanks so you're limited to repairing yours or buying a used original or maybe an nos tank.
There certainly are other vacuum tanks you can use but what you choose might depend on if you're concerned about the 'originality' of your car.
Getting the old tank out in any case is a bit of a hassle that involves moving the master cylinder out of the way. The tank can't be dropped down under the car and is too odd shaped to bring into the engine compartment without moving the master cylinder.
Good Luck!
Glad your here!
Regards,
Alan
Always like to see pictures of member's cars!
Welcome!
First Post!
And a 72!!! Nice!
The tanks do sometimes end up leaking. Some folks have success in repairing them depending just what the problem is…. rust ?, a crack?, a leak at one of the hose connection pipes?.
You're right. There isn't anyone making reproductions of these tanks so you're limited to repairing yours or buying a used original or maybe an nos tank.
There certainly are other vacuum tanks you can use but what you choose might depend on if you're concerned about the 'originality' of your car.
Getting the old tank out in any case is a bit of a hassle that involves moving the master cylinder out of the way. The tank can't be dropped down under the car and is too odd shaped to bring into the engine compartment without moving the master cylinder.
Good Luck!
Glad your here!
Regards,
Alan
Always like to see pictures of member's cars!
Last edited by Alan 71; Aug 23, 2016 at 01:54 PM.
Thread Starter
5th Gear
Joined: Aug 2016
Posts: 5
Likes: 0
Hi s,
Welcome!
First Post!
And a 72!!! Nice!
The tanks do sometimes end up leaking. Some folks have success in repairing them depending just what the problem is…. rust ?, a crack?, a leak at one of the hose connection pipes?.
You're right. There isn't anyone making reproductions of these tanks so you're limited to repairing yours or buying a used original or maybe an nos tank.
There certainly are other vacuum tanks you can use but what you choose might depend on if you're concerned about the 'originality' of your car.
Getting the old tank out in any case is a bit of a hassle that involves moving the master cylinder out of the way. The tank can't be dropped down under the car and is too odd shaped to bring into the engine compartment without moving the master cylinder.
Good Luck!
Glad your here!
Regards,
Alan
Always like to see pictures of member's cars!
Welcome!
First Post!
And a 72!!! Nice!
The tanks do sometimes end up leaking. Some folks have success in repairing them depending just what the problem is…. rust ?, a crack?, a leak at one of the hose connection pipes?.
You're right. There isn't anyone making reproductions of these tanks so you're limited to repairing yours or buying a used original or maybe an nos tank.
There certainly are other vacuum tanks you can use but what you choose might depend on if you're concerned about the 'originality' of your car.
Getting the old tank out in any case is a bit of a hassle that involves moving the master cylinder out of the way. The tank can't be dropped down under the car and is too odd shaped to bring into the engine compartment without moving the master cylinder.
Good Luck!
Glad your here!
Regards,
Alan
Always like to see pictures of member's cars!
Team Owner
Joined: Sep 2006
Posts: 31,160
Likes: 4,236
From: Westminster Maryland
Hi s,
As I said getting the old one out is a project.
On a std brake car the master cylinder needs to be unbolted from the firewall pulled forward and then pushed toward the engine.
On a pwr brake car the booster is in the way too.
Good Luck!
Regards,
Alan
As I said getting the old one out is a project.
On a std brake car the master cylinder needs to be unbolted from the firewall pulled forward and then pushed toward the engine.
On a pwr brake car the booster is in the way too.
Good Luck!
Regards,
Alan
Race Director
Joined: Apr 2011
Posts: 11,183
Likes: 3,334
From: North of Toronto - Ontario
I've never opened a tank up but always figure it's just a plain box (no valves or anything???)
If it's not completely rotten or anything I would think using one of the kits for sealing a gas-tank should work. The type you pour in and then rotate the tank to coat the insides and let it dry. I think they even make smaller ones for motorcycle tanks that would be lots. POR15 etc.
Any yes, removing that tank is a PIA
https://www.corvetteforum.com/forums...k-removal.html
M
If it's not completely rotten or anything I would think using one of the kits for sealing a gas-tank should work. The type you pour in and then rotate the tank to coat the insides and let it dry. I think they even make smaller ones for motorcycle tanks that would be lots. POR15 etc.
Any yes, removing that tank is a PIA
https://www.corvetteforum.com/forums...k-removal.html
M
Melting Slicks
Joined: Mar 2005
Posts: 2,093
Likes: 297
From: Midlothian VA
It only hold air/vacuum - sealing it is easy as there are many options.
As stated above though - getting to it is the trick.
IF you can get it out - pressurize it OR hold it under water OR fill it with water to check for leaks.
As stated above though - getting to it is the trick.
IF you can get it out - pressurize it OR hold it under water OR fill it with water to check for leaks.
Melting Slicks
Joined: Oct 2012
Posts: 2,156
Likes: 273
From: Dunedin NZ.
I had a leak in the vac tank in my '70. I disconnected the hoses from the tank and blocked off the outlets, connected a compressor to the inlet, pressurised the tank to 5 psi quickly found a split in the tank on the outer side. Luckily I could reach the split with my fingers and because removing the tank is such a pain I opted to patch the split with a piece of fibreglass cloth soaked in resin, this worked a treat.
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Team Owner
Joined: Jun 2001
Posts: 23,359
Likes: 1,058
From: Virginia USA
So here's a thought. If the tank is leaking why not bypass it? The only reason for the tank is to store vacuum to allow the headlights and wiper door (if equipped) to raise and lower, I think the owners manual or I read somewhere, 3 times without starting the engine????????
I don't think I've ever been in the situation where I needed to do that.
What do you guys think?
I know mine leaks but just looking at the location I've not messed with it. Just seeing this thread reminded me of it and I have my engine out for a clutch swap and other things and now would be a perfect time to do this while waiting on parts. If anyone has ever bypassed it without any negative effects I may just do that. My wiper door and headlights open and close fine at this time (after a lot of work lol).
I don't think I've ever been in the situation where I needed to do that.
What do you guys think?
I know mine leaks but just looking at the location I've not messed with it. Just seeing this thread reminded me of it and I have my engine out for a clutch swap and other things and now would be a perfect time to do this while waiting on parts. If anyone has ever bypassed it without any negative effects I may just do that. My wiper door and headlights open and close fine at this time (after a lot of work lol).
Team Owner
Joined: Sep 2006
Posts: 31,160
Likes: 4,236
From: Westminster Maryland
Hi ta,
I believe you're right thinking that the headlight and wiper door system can operate without the tank.
The purpose of the tank is to supply a limited amount of vacuum without starting the engine.
" My wiper door and headlights open and close fine at this time (after a lot of work lol)."
Working headlight doors and wiper door are a beautiful thing!
Regards,
Alan
I believe you're right thinking that the headlight and wiper door system can operate without the tank.
The purpose of the tank is to supply a limited amount of vacuum without starting the engine.
" My wiper door and headlights open and close fine at this time (after a lot of work lol)."
Working headlight doors and wiper door are a beautiful thing!
Regards,
Alan
Last edited by Alan 71; Aug 24, 2016 at 05:19 PM.
Team Owner
Joined: Jan 2006
Posts: 37,637
Likes: 3,114
From: Crossville TN
There is no need to open up the reservoir tank. It is a VACUUM reservoir...which means that it is leaking INTO the tank, not OUT OF the tank.
If you find damaged areas on the tank, patch them with epoxy on the OUTSIDE of the tank. Clean the surface, cut out or wire brush off any loose stuff, put a patch of JB Weld stick epoxy over the area to be sealed...and make it look as purty as you can. Paint it satin black, if you want. Then just put it back in place, once you are sure that it is sealed, again.
If you want to replace it (can't imagine why), you can find good used tanks at most Corvette parts swap meets.
If you find damaged areas on the tank, patch them with epoxy on the OUTSIDE of the tank. Clean the surface, cut out or wire brush off any loose stuff, put a patch of JB Weld stick epoxy over the area to be sealed...and make it look as purty as you can. Paint it satin black, if you want. Then just put it back in place, once you are sure that it is sealed, again.
If you want to replace it (can't imagine why), you can find good used tanks at most Corvette parts swap meets.
Instructor
Joined: Dec 2011
Posts: 159
Likes: 12
From: Bushnell Florida
On my 74 I did bypass the vacuum tank. Mine is in the front of the car, so it was easy to get to. I was having trouble with the lights going up and down. I used a Y fitting. The main vacuum line into the top the Y and the headlight regulator lines to the other ends. Boom lights work fine now.