15 replies to this topic

[Mycol]

I got a second hand AA PC for 100$ right before the pandemic and it’s worked well until recently .

It’s got a slight leak by one of the “handles” on the bottom . After it gets up to 15psi or so I’ve seen just a little puff of steam seep out . I’ve watched it come from between the lid and the bottom with flashlight . I’ve scrubbed the seal with fine steel wool. I’ve applied and reapplied vasoline around it .

Replaced the safety plug too just in case .

Am I screwed ? Time to move on ? I’ve got my money out of it and have a backup presto still in the box but I’m still bummed if this is he case .

Any suggestions are appreciated

[DonShadow]

If it’s coming from the seal I wouldn’t worry about it personally. Those seals are rarely perfect and a bit of steam seeping out isn’t abnormal in my experience, even with newer machines. As long as you’re certain it’s the seal that’s leaking and there aren’t any hairline cracks I think you’re fine. Whenever I’ve cleaned a seal on an AA in the past, it always leaks for awhile because I think cleaning removes a beneficial gummy film that develops with repeated use. Page 6 of this manual states that leaks are not abnormal and should correct over time:

https://www.allameri.../Product_49.pdf

[Juthro]

I've had a similar experience with cleaning the sealing surface on an AA.  I had removed the build up with a scotch brite pad, and it started leaking on the very next cycle. I smeared a really light coating of vegetable oil around the sealing surface on the base before the next run, and it's been sealing fine again ever since. I think it's like DonShadow said, it makes kind of a thin rubbery gasket once it has cooked into place.  Also take care to make sure the lid is even and level with the base and try to tighten in down in a pattern, kind of like you would tighten down head bolts or the wheel of a car, 

 

Does the unit still hold 15 psi well enough to run a successful cycle without risk of running out of water?  If so I would say you are fine, and I would bet that with a couple of cycles of lightly oiling the sealing surface it will fill start to seal properly again.

 

I hope my ramblings helped some, and good luck :)

 

 

 

 

 

[Myc]

Plus 1 for using vegetable oil to lubricate the gaskets.

 

Just like with changing the oil in your car - you always lubricate the gasket of the new oil filter with a smear of motor oil.  This keeps the gasket from developing distortions or wrinkles during installation. And it allows the gasket to move a little with changes in temperature without compromising the seal.

 

This is also true of most "nuts and bolts" assemblies. When building a bicycle - every single threaded connection needs a small amount of grease. Otherwise those "dry" nuts and bolts will tick and ping - damaging the fastener and (potentially) surrounding mated surfaces. In worst case instances a dry connection can result in metal fatigue and catastrophic failure under stress.

And remember - a little goes a long way. You don't have to bathe the parts in lubricant. Just getting a tiny dab on the leading threads during assembly will do the trick.

[Mycol]

Ok cool thanks for the input everyone . I think I will wash off the vasoline and use some vegetable oil on their eand give Tim a few more runs while monitoring it closely .

I think that it will hold 15 psi without running out of water . Will keep you guys posted

[DonShadow]

I’m pretty sure the AA manual recommends using petroleum jelly aka Vaseline on the seals, but I don’t think it matters which one you use ultimately. I’ve used both with no noticeable differences—both will keep the mating surfaces from sticking and both will result in a kind of gummy buildup that aids the seal. I suspect that part of this buildup is actually residue and sugars from the contents of the canner.

It would have to be a serious leak to cause your canner to run out of water over a 90 minute cycle. Maybe take note of the water level and see how much you lose after the cycle. I typically start with about 1.5” of water if I’m doing jars. My canners usually sputter/leak a tiny bit from the seal but I lose very little water over the course of 90 minutes… half inch from the initial 1.5” at the most. The majority of loss will be coming from the vent pipe without a doubt.

[shiftingshadows]

I would not use just any scotch brite pad ---too rough IMO, page 7says:

 

"It is also important to periodically wipe off the metal-to-metal seal with a clean towel to remove any build-up of foreign material trapped in the lubricant. You may use 0000 grade steel wool and carefully go around the seal to remove any build-up of hardened lubricant. However, avoid hard scrubbing of the metal-to-metal seal to prevent damage."

 

https://duckduckgo.c...7b71b513bdc.jpg

Edited by shiftingshadows, 01 January 2023 - 02:30 AM.

[Myc]

I was kind of astonished that petroleum jelly was recommended as a lubricant for the gaskets - since petroleum jelly tends to break down (dissolve) rubber and similar materials.

That being said, I do not know the composition of the gasket materials employed with the AA pressure cooker and they may be chemically resistant to petroleum jelly.

[Mycol]

All American doesn’t use rubber gaskets On the rim like a presto I have . I used to use vegetable oil on my presto’s gasket .

AA has a rubber safety plug but the rim of the lid and the edge of the “pot” are beveled and form their own seal .

I will add another small coating of vasoline .

Thanks for the links to the manual Don .

I haven’t ran it in a few days but I will tonight .

[Juthro]

There is no gasket on an AA, it's a tapered metal to metal seal.

 

EDIT: Mycol beat me to the punch

Edited by Juthro, 01 January 2023 - 03:04 PM.

[Juthro]

I would not use just any scotch brite pad ---too rough IMO

 

 

0000 steel wool is considered to be about 400 grit equivalent.  Green scotch brite is around 600 grit, blue pads are around 1000 grit, and the white scotch brite pads are considered to be between 1200 and 1500 grit.

[Mycol]

How does shaking work with the 1/4 pint? Looks as if you have those totally full?

Got it running now after another application of vasoline and so far she’s running like a champ.


Edit: ok now it’s giving up a tiny spittle from the area I’d marked. I’m confident that it won’t be near enough to run the thing dry though .

Edited by Mycol, 04 January 2023 - 05:22 PM.

[Mycol]

Should there be negative pressure after it cools down ?

I removed the weight and it proceeds to suck air in . Haven’t noticed that before .

[Juthro]

Should there be negative pressure after it cools down ?

I removed the weight and it proceeds to suck air in . Haven’t noticed that before .

 

My AA 921 will pull a slight vacuum with the weight on when it cools down. I can see it on my gauge, zero pressure isn't quite on the stop pin for the indicator needle.

[Severian]

Woops didn't lubricate my new gasket for my presto - good thing I saw that info before running it abunch of cycles!

[shiftingshadows]

Presto manual page 5 for 16 quart canner:

 

"9. Place the cover on the canner; use only the cover that came with the canner when it was new. Do not pressurize the canner until the cover handles are aligned with the body handles. If the cover is difficult to open or close, use a pastry brush or paper towel to apply a light coating of vegetable oil to the underside of the canner body lugs. Do not oil the sealing ring...."

 

choose manual for your model here:

 

https://www.gopresto...p?category_id=3

Edited by shiftingshadows, 06 January 2023 - 01:42 PM.