Vacuum Tank Repair...

Hi all!
The boy and I replaced the Vacuum Actuator Seals (Thanks again Don!) and now we want to tackle the leak in the Vacuum Tank (the one in the driver’s side wheel well).
Ours has the TWO inputs.

Is there a “Fix a Flat” type of spray that can be used to repair these? How does one go about doing this?

If they leak it is generally because they are rusted out along the seam. There’s no good repair for that. The good news is WCCC sells used ones for a very affordable price.


Thanks man. Surely there’s a repair kit? A fix?
I don’t mind replacing the tank…but I mean… it seems like it’d be a simple thing. Maybe JB Weld or something?
How do you track down the leak?

Hello ssava, I am converting to electric actuators. You can have mine for free if you pay shipping. Send me a check when you receive it. Shoot me a PM if you are interested. Jim R.

Put compressed air into it, maybe 1 PSI. Then submerge it in a trash can full of water.


Hey, you can not beat free, but if you just want to find the leak for the heck of it, submerge tank in water and add air to inlet on tank and watch for bubbles.
Edit–looks like I took to long to type

Your problem may well lay with the 2 port vacuum valve. If it has gone bad the only fix is to replace the tank. This style tank was a 67 only part.

Randy Goodling
CCOA #95

Thank you all! And thank you 19cougar68 for the amazing offer.

My son really wants to give fixing it a try as that’s kind of the reason why we got her. But if we can’t… we will DEFINITELY take you up on the offer.
So generous.

We will take the tank out and submerge it and see.

The tank on my 68 had some pinholes from rust. I painted it with truck bedliner and that sealed it up tight.

Keep in mind that this is a vacuum tank, it holds negative pressure if you want to think of it that way. So it will pull any coating on the outside in.

I am in need of a tank for the 68 that I am restoring
PM sent .
Thanks Scott

Dunk the tank to find the leak and see how bad it is, if it’s rusted don’t mess with it just replace it. If it’s just a pin hole you can just patch it up by either welding or using an epoxy like jb weld.

Thanks all!
The tank didn’t show any leaks. Dunked it and everything.
Also. It held vacuum for an hour without any change.

But, when we hook it into the system… the headlights don’t go up and down as easily.

So, my son has decided we should bypass the tank for now as they’re moving really well.
https://www.youtube.com/watch?v=5CYvX6EDzNg

Of course, we’d LOVE to get the tank in there if anyone has suggestions as to why we would lose vacuum with the tank?
It’s got the TWO ports… in case I didn’t mention.

Likely the vacuum hose leading to the tank has a hole or is melted or cracked somewhere. You have a working tee check valve correct?



Yeah. We’ve tested it. But it’s also my 17 year old son, so let’s DOUBLE check it… just in case.
:slight_smile:

We have been letting these out the door just a few at a time over the last year but now we have a good supply in stock.

https://secure.cougarpartscatalog.com/17051/31132/shaft-seal-kit-headlight-vacuum-actuator-repro-1967-1970-mercury-cougar.html?sessionthemeid=26