I've used the Bike Pump system on 10 litre kegs for two reasons:
- The natural carbonation puts a CO2 blanket on top of the brew and that protects the brew.
- The brew doesn't last long enough to spoil due to oxygenation.
- My 10 litre PB's don't have a CO2 injector point and the method calls for the top to be slackened off anyway.
https://www.amazon.co.uk/dp/B002R69T84/?tag=skimlinks_replacement-20
I've modified them by installing a stainless-steel valve adjacent to the top like this ...
https://www.amazon.co.uk/dp/B01DJVDMVA/?tag=skimlinks_replacement-20
I've now gone all "posh" and use a Sodastream CO2 System on all of my PB's. The tops look like this ...
View attachment 16202
As you can see, I've cut the end off the Bike Pump so that I can use it with the Sodastream Bottle as per this photo.
View attachment 16203
The tubing from the Bike Pump fits into the Manifold.
I carbonate the PB's and Growlers with a maximum of 1g per litre of brewing sugar just to keep anything nasty out whilst they are carbonating and conditioning. When they're in use I use 5psi of pressure 'cos I hate a "gassy" brew.
Like a lot of my stuff, it looks rough -
but it works!
PS
I also reckon that you may have a leak! I use Vaseline to seal the "O" rings on the PB's 'cos it doesn't affect the taste of the brew.