has anyone ever had trouble putting air in/getting them to seal? i can put air in one of mine fine, but the other i cannot get my pump to seal on, i can still pump it up, but there is air escaping around it.
If you have’nt already done so, try applying a little teflon tape to the valve threads before you screw on the extender.
the issue is coming from the end of the extender and not where the two meet. i would have said it was my pump but it works fine on the front one, maybe need a new extender?
That is not all that uncommon, the shop bike at my lbs usually requires a person to hold the pump head on the extender or it leaks. Maybe extenders not machined down to small at the end or fresh o-rings or whatever is in the head of the pump to make a better seal. My serfas pump has no problem but it is not that old and does not see much use.
I bet it’s leaking from the extender and tube and not from the pump. It’s hard to tell where it’s coming from. Try the teflon tape.
I have had problems with extenders, including the Zipp extender ends that, for some reason, are shaped differently than a normal presta valve end…
I have experienced what you are talking about and in the case of the bike shop pump it is definitely not the extender, it is certainly the interface of the pump head and the extender. It leaks when directly attached to a valve stem with no extender. It is the “community pump” so to speak so it gets used and abused. You have to hold it just right or it leaks around the edges. They have quite a few community pumps that are like this. I guess it might be good advise to not let just anyone touch your pump head 