I just got a couple of Pin Lock kegs. The o-rings are sticky so I think it may have had soda in them before so I will replace those but how do I know if the poppits need to be replaced to?
take them out, look at them and see if the rubber seals look worn out. If in doubt, replace them. Its a real pain to deal with bad poppits once the brew is in the keg.
Rig a way to presurize the keg with air.
If the poppet leaks, despite using a little keg lube, replace it.
Life is too short to have a weak, leaky, poppet.
+1 pressurize and check. I would still replace the O rings, regardless, but this way you know id you need to order poppets as well.