kegs still won't seal

[Paulinuke]

I posted earlier today about poppets. Well I found what I needed about an hour from the house so I went for a ride. I just came up from the cellar after about 2 hours of work. I have two of the four kegs completely cleaned and totally rebuilt. My problem is that on one of the kegs the poppet valves are still leaking. I tried depressing them and letting them go and knocking on them, they just won't seal up. Only one of the kegs seams to be holding pressure. I won't know until I go back down to check it in a few hours.
I replaced both dip tube o-rings, both poppets, and both post o-rings, prior to putting it back together evertything was cleaned in PBW and lubricated with keg lube. I need help. Paul

 

[Bobby_M]

Pull the leaky post off, remove the poppet and look inside the post where the poppet gasket hits the top of the post. See if there are any nicks or deposits. A little keg lube on the poppet top can work wonders also.

 

[bradsul]

Have you tried a little bit of keg lub on the poppet valve seals as well?

 

[BierMuncher]

…
I replaced both dip tube o-rings, both poppets, and both post o-rings, prior to putting it back together evertything was cleaned in PBW and lubricated with keg lube. I need help. Paul

Are you positive you replaced with the exact same size poppet?

 

[Paulinuke]

I did lube the top of the poppets, and when compared side by side they are identical, except the new ones are yellow. I guess I will take the posts back off and check the insides for problems. Paul

 

[Germey]

Did you Crank up the pressure to 20-30 lbs. I find that with new seals, that can help get everything seated, then bleed off the pressure after it has sat for a while.

 

[Paulinuke]

Thanks everyone, I finally did get that particular kegs poppets to seal, however after pressurizing it I sprayed on some starsan to check for leaks and found that the base of the threads where the gas post is has a leak, it must be a cracked weld or something. Does anyone have any suggestion on what to do with a corny that wont hold pressure? Paul

 

[BrewPuppy]

sometimes those buggers (poppets) need a little encouragement to seat. I don't know if this is a good idea or not, but I was having hell with one and I solved it by:

1. loading up the poppet with lube to "start" the seal.
2. adding about 1 gallon of hot water (not boiling) to the keg.
3. bumping up the pressure to about 20 psi. remove the connection.
4. turning the keg upside down.
5. waiting and hoping and praying.

It worked for me. I don't know if it was the lube, the hot water, the pressure, or all three. All I know is that the poppet took a seat.

After that, I had to disassemble to get rid of the excess lube and re-sanitize.

Just be sure to keep the poppet and stem sets together because there is a chance that you have created a unique set.

 

[bradsul]

Thanks everyone, I finally did get that particular kegs poppets to seal, however after pressurizing it I sprayed on some starsan to check for leaks and found that the base of the threads where the gas post is has a leak, it must be a cracked weld or something. Does anyone have any suggestion on what to do with a corny that wont hold pressure? Paul

Try some teflon tape on the threads and see if that helps.